Quick Recipe Version (TL;DR)

Yield: 4 servings
Prep Time: 25 minutes (plus 1 hour chilling)
Cook Time: 1 hour 15 minutes
Total Time: 2 hours 15 minutes

Quick Ingredients

6 cups water (or 4 cups water + 2 cups whole milk)
1 1/2 cups coarse yellow polenta (not instant)
1 1/2 tsp kosher salt, plus more to taste
3 tbsp unsalted butter, plus more for pan (optional)
1 cup finely grated Parmesan cheese
3 tbsp olive oil (for polenta squares)
2 tbsp olive oil (for ragù)
2 tbsp unsalted butter (for ragù)
1 medium onion, 1 small carrot, 1 small celery stalk (all finely diced)
3 cloves garlic, minced
1 1/2 lb mixed mushrooms, chopped
2 tbsp tomato paste
1/2 cup dry red wine (or extra broth)
1 1/2 cups vegetable broth
Thyme, rosemary, bay leaf, red pepper flakes (optional)
1 tsp soy sauce or tamari
Fresh parsley and extra Parmesan for serving

Do This

1. Cook polenta: Boil water, whisk in polenta and salt, then simmer 25–30 minutes until thick and creamy. Stir in butter, Parmesan, and pepper.
2. Set polenta: Spread hot polenta into a parchment-lined 9×13-inch pan. Smooth top and chill at least 1 hour until firm.
3. Start ragù: Sauté onion, carrot, and celery in oil and butter until soft. Add garlic, then mushrooms; cook until browned and most liquid has evaporated.
4. Build flavor: Stir in tomato paste, herbs, and red pepper flakes. Deglaze with wine, then add broth, soy sauce, and bay leaf. Simmer 25–30 minutes until rich and saucy.
5. Crisp polenta: Cut chilled polenta into squares. Brush with oil and bake at 425°F (220°C) for 20–25 minutes, turning once, until golden and crisp.
6. Finish ragù: Remove bay leaf, adjust seasoning, and stir in chopped parsley.
7. Serve: Top hot crispy polenta squares with mushroom ragù, extra Parmesan, parsley, and a drizzle of olive oil.

Why You’ll Love This Recipe

Comforting and elegant: Crispy, cheesy polenta meets a deeply savory slow-simmered mushroom ragù.
Make-ahead friendly: Cook and chill the polenta in advance, then crisp and serve when you are ready.
Vegetarian yet hearty: Rich enough to satisfy meat-lovers thanks to umami-packed mushrooms and Parmesan.
Perfect for guests: Rustic, beautiful presentation with cozy, restaurant-level flavor.

Grocery List

Produce: 1 medium yellow onion, 1 small carrot, 1 small celery stalk, 3 cloves garlic, 1 1/2 lb mixed mushrooms, fresh flat-leaf parsley, fresh thyme and rosemary (or dried)
Dairy: Unsalted butter, whole milk (optional for creamier polenta), Parmesan cheese
Pantry: Coarse yellow polenta (not instant), olive oil, vegetable broth, dry red wine (or extra broth), tomato paste, soy sauce or tamari, bay leaf, red pepper flakes, kosher salt, black pepper

Full Ingredients

Crispy Polenta Squares

6 cups water or 4 cups water + 2 cups whole milk (for creamier polenta)
1 1/2 cups coarse yellow polenta (stone-ground if possible; not instant or quick-cooking)
1 1/2 tsp kosher salt, plus more to taste
3 tbsp unsalted butter
1 cup finely grated Parmesan cheese (about 2 oz), plus more for serving
1/4 tsp freshly ground black pepper
2–3 tbsp olive oil (for brushing the pan and polenta squares)
Butter for greasing the pan (optional, for extra flavor)

Slow-Simmered Mushroom Ragù

2 tbsp olive oil
2 tbsp unsalted butter
1 medium yellow onion, finely diced (about 1 cup)
1 small carrot, finely diced (about 1/2 cup)
1 small celery stalk, finely diced (about 1/2 cup)
3 cloves garlic, minced
1 1/2 lb mixed mushrooms, cleaned and chopped (such as cremini, shiitake, and portobello; about 7–8 cups chopped)
2 tbsp tomato paste
1/2 cup dry red wine (or use additional broth)
1 1/2 cups vegetable broth
1 tsp fresh thyme leaves or 1/2 tsp dried thyme
1 tsp finely chopped fresh rosemary or 1/2 tsp dried rosemary
1 bay leaf
1/4 tsp red pepper flakes (optional, for gentle heat)
1 tsp soy sauce or tamari (adds depth and umami)
1/2 tsp kosher salt, plus more to taste
Freshly ground black pepper, to taste
2–3 tbsp chopped fresh flat-leaf parsley, plus more for garnish

To Serve

Extra finely grated Parmesan cheese
Extra-virgin olive oil, for drizzling
Additional chopped fresh parsley

Step-by-Step Instructions

Step 1: Cook the Polenta

In a large, heavy-bottomed pot, bring the water (or water and milk) to a gentle boil over medium-high heat. Whisk in the kosher salt. Slowly pour in the polenta in a thin stream while whisking constantly to prevent lumps from forming. Once all the polenta is added, continue whisking for 1–2 minutes until the mixture begins to thicken.

Reduce the heat to low so the polenta is just barely bubbling. Switch to a wooden spoon or heatproof spatula and cook, stirring frequently and scraping the bottom of the pot, for 25–30 minutes. The polenta is done when it is thick, creamy, and pulls away slightly from the sides of the pan. Stir in the butter, Parmesan, and black pepper. Taste and adjust salt if needed.

Step 2: Chill the Polenta into a Firm Slab

While the polenta cooks, line a 9×13-inch baking dish with parchment paper, leaving some overhang for easy lifting later. Lightly grease the parchment and sides of the pan with a bit of butter or olive oil.

When the polenta is finished and still hot, pour it into the prepared baking dish. Use a spatula to spread it into an even layer, smoothing the top as much as possible. Aim for a thickness of about 3/4 inch. Let the polenta cool at room temperature for 15–20 minutes, then transfer the pan to the refrigerator. Chill until very firm, at least 1 hour (or up to 24 hours). The firmer the polenta, the easier it will be to cut clean squares that crisp nicely.

Step 3: Build the Mushroom Ragù Base

When the polenta is chilling, begin the ragù. In a large, wide skillet or Dutch oven, heat the olive oil and butter over medium heat until the butter has melted and is foamy. Add the diced onion, carrot, and celery. Cook, stirring occasionally, for 8–10 minutes, until the vegetables are very soft and lightly golden around the edges.

Add the minced garlic and cook for 30–60 seconds until fragrant. Increase the heat to medium-high and add the chopped mushrooms. At first the pan will look very full; that is fine. Cook, stirring occasionally, for 10–12 minutes. The mushrooms will release their liquid, then gradually that liquid will cook off and the mushrooms will begin to brown. Keep cooking until most of the moisture has evaporated and you see some golden-brown bits on the bottom of the pan.

Step 4: Simmer the Ragù Until Rich and Saucy

Stir the tomato paste into the mushroom mixture and cook for 1–2 minutes, stirring constantly, until the paste darkens slightly in color and coats the vegetables. Add the thyme, rosemary, and red pepper flakes (if using), and cook for another 30 seconds.

Pour in the red wine and use a wooden spoon to scrape up any browned bits from the bottom of the pan. Let the wine simmer for 2–3 minutes, until reduced by about half. Add the vegetable broth, soy sauce, bay leaf, 1/2 tsp kosher salt, and a few grinds of black pepper. Stir well, bring to a gentle simmer, then reduce the heat to low. Let the ragù simmer uncovered for 25–30 minutes, stirring occasionally, until it is thick, glossy, and deeply flavored. If it ever looks too dry, splash in a bit more broth or water; if it is too soupy near the end, let it simmer a little longer.

Step 5: Cut and Crisp the Polenta Squares

About 10–15 minutes before the ragù is finished, preheat your oven to 425°F (220°C). Line a large baking sheet with parchment paper or lightly oil it. Lift the chilled polenta slab out of the baking dish using the parchment overhang and place it on a cutting board. Use a sharp knife to cut it into 12 even squares or rectangles, roughly 2 x 3 inches each.

Arrange the polenta pieces on the prepared baking sheet, leaving a little space between each one. Brush or drizzle both sides of each square with olive oil. Bake for 20–25 minutes, turning the pieces over halfway through, until the edges are crisp and the surfaces are deep golden brown. For extra crunch, you can broil them for the final 1–2 minutes, watching closely to avoid burning.

Step 6: Finish the Ragù with Fresh Parsley

When the ragù has reduced to a thick, spoonable consistency, remove the bay leaf. Taste and adjust seasoning with additional salt and pepper as needed. Turn off the heat and stir in 2–3 tbsp of chopped fresh parsley. The herbs should remain bright and fresh-tasting, so add them right at the end.

If you prefer a slightly silkier texture, you can stir in an extra teaspoon of butter or a splash of olive oil at this stage. Keep the ragù warm over very low heat while the polenta squares finish crisping.

Step 7: Plate, Garnish, and Serve

To serve, place 3–4 hot crispy polenta squares on each plate (depending on appetite and whether this is a main or starter). Spoon a generous amount of the mushroom ragù over the top, letting some spill attractively over the sides. Sprinkle with extra grated Parmesan and more chopped parsley. Finish with a light drizzle of good extra-virgin olive oil for shine and aroma.

Serve immediately while the polenta is crisp on the outside and tender inside, and the ragù is hot and fragrant. This dish pairs wonderfully with a simple green salad and a glass of the same red wine you used in the sauce.

Pro Tips

Use coarse polenta for the best texture. Fine or instant polenta will not hold its shape and crisp as nicely. Look for “coarse” or “stone-ground” on the label.
Stir the polenta often. Frequent stirring prevents lumps and sticking, and gives you ultra-creamy polenta before it is chilled.
Cook the mushrooms long enough. Let them release their liquid and then brown; this step is key for deep, meaty flavor in a vegetarian ragù.
Chill thoroughly before cutting. If the polenta is still warm or soft inside, the squares will break apart instead of crisping cleanly.
Adjust the ragù consistency at the end. If it is too thick, add a splash of broth; if it is too loose, simmer uncovered for a few more minutes.

Variations

Creamy bowl style: Skip the chilling and crisping. Serve the polenta soft and spoonable in bowls, topped directly with the mushroom ragù and herbs.
Extra decadent: Stir 1/4 cup heavy cream or a spoonful of mascarpone into the finished ragù, and add a bit more Parmesan to the polenta.
Smoky, non-vegetarian twist: Sauté a few diced strips of pancetta or bacon with the onion, carrot, and celery for a smoky base, and use chicken stock instead of vegetable broth.

Storage & Make-Ahead

The polenta can be made and chilled up to 24 hours in advance. Keep it covered in the refrigerator in the baking dish. Once cut and baked, leftover crispy polenta squares can be cooled and stored in an airtight container in the fridge for up to 3 days. Reheat on a parchment-lined baking sheet at 400°F (200°C) for 10–15 minutes until hot and re-crisped.

The mushroom ragù keeps very well: store it in an airtight container in the refrigerator for up to 4 days, or freeze for up to 3 months. Reheat gently on the stovetop, adding a splash of water or broth if it has thickened too much. This makes the dish ideal for preparing components ahead of time and assembling just before serving.

Nutrition (per serving)

Approximate values per serving (1/4 of the recipe): about 550 calories, 34 g fat, 55 g carbohydrates, 15 g protein, 4 g fiber, and 900 mg sodium. These numbers will vary depending on the exact brands and amounts of ingredients you use and how much extra Parmesan and olive oil you add at the table.

Crispy Polenta Squares With Slow-Simmered Mushroom Ragu