Quick Recipe Version (TL;DR)
Quick Ingredients
- 4 large portobello mushroom caps (about 5–6 inches wide)
- 3 tbsp extra-virgin olive oil, divided
- 1/2 tsp kosher salt, divided
- 1/2 tsp black pepper, divided
- 10 oz (about 8 packed cups) fresh baby spinach
- 4 cloves garlic, minced
- 1/4 tsp crushed red pepper flakes (optional)
- 1 cup (240 g) whole-milk ricotta
- 1/3 cup (30 g) grated Parmesan
- 1/2 tsp Italian seasoning (or dried oregano)
- 1 large egg
- 1 cup (240 g) marinara sauce
- 1/2 cup (56 g) shredded mozzarella
- 2 tbsp chopped fresh basil or parsley (optional)
- Side salad: 5 oz (about 5 packed cups) mixed greens, 1 small cucumber, 1 cup cherry tomatoes
- Salad dressing: 3 tbsp extra-virgin olive oil, 1 1/2 tbsp lemon juice, 1 tsp Dijon mustard, 1 tsp honey, 1/4 tsp kosher salt, 1/4 tsp black pepper
Do This
- 1. Heat oven to 425°F (218°C). Line a baking sheet with parchment.
- 2. Remove portobello stems/gills, brush caps with oil, season; roast 10 minutes, gill-side up.
- 3. Sauté garlic in oil, wilt spinach, then squeeze very dry and chop.
- 4. Mix ricotta, Parmesan, egg, seasoning, spinach mixture, salt/pepper.
- 5. Flip mushrooms, fill with ricotta mixture, top with marinara and mozzarella.
- 6. Bake 12–15 minutes until hot and melty; broil 1–2 minutes if you want browning.
- 7. Toss lemony salad and serve alongside the stuffed mushrooms.
Why You’ll Love This Recipe
- Big, satisfying portions with cozy lasagna-like vibes, but without the fuss.
- The spinach-garlic ricotta filling stays creamy while the mushroom roasts up meaty and tender.
- Marinara and mozzarella give you that classic Italian comfort-food finish.
- The lemony side salad cuts through the richness and makes the whole meal feel bright and balanced.
Grocery List
- Produce: 4 large portobello caps, baby spinach (10 oz), garlic, lemon, mixed greens (5 oz), cucumber, cherry tomatoes, fresh basil or parsley (optional)
- Dairy: whole-milk ricotta, Parmesan, shredded mozzarella, 1 large egg
- Pantry: marinara sauce, extra-virgin olive oil, Dijon mustard, honey, kosher salt, black pepper, Italian seasoning (or oregano), crushed red pepper flakes (optional)
Full Ingredients
For the stuffed portobello mushrooms
- 4 large portobello mushroom caps (about 5–6 inches wide)
- 3 tbsp extra-virgin olive oil, divided
- 1/2 tsp kosher salt, divided
- 1/2 tsp freshly ground black pepper, divided
- 4 cloves garlic, minced
- 10 oz (about 8 packed cups) fresh baby spinach
- 1/4 tsp crushed red pepper flakes (optional)
- 1 cup (240 g) whole-milk ricotta
- 1/3 cup (30 g) grated Parmesan
- 1/2 tsp Italian seasoning (or 1/2 tsp dried oregano)
- 1 large egg
- 1 cup (240 g) marinara sauce
- 1/2 cup (56 g) shredded mozzarella
- 2 tbsp chopped fresh basil or parsley (optional, for serving)
For the lemony side salad
- 5 oz (about 5 packed cups) mixed greens
- 1 small cucumber, thinly sliced
- 1 cup cherry tomatoes, halved
For the lemon dressing
- 3 tbsp extra-virgin olive oil
- 1 1/2 tbsp fresh lemon juice
- 1 tsp Dijon mustard
- 1 tsp honey
- 1/4 tsp kosher salt
- 1/4 tsp freshly ground black pepper
Step-by-Step Instructions
Step 1: Prep the oven and mushrooms
Arrange a rack in the center of the oven and preheat to 425°F (218°C). Line a rimmed baking sheet with parchment paper (or foil for easy cleanup).
Clean the portobellos by wiping them with a damp paper towel. Remove the stems. Use a spoon to gently scrape out the dark gills (this helps reduce moisture and keeps the filling a pretty color).
Step 2: Roast the portobello caps to remove excess moisture
Place the mushroom caps on the baking sheet gill-side up. Brush with 1 1/2 tbsp of the olive oil and season with 1/4 tsp kosher salt and 1/4 tsp black pepper.
Roast for 10 minutes. You’ll likely see some liquid collect in the caps; that’s normal and helps keep the mushrooms tender.
Step 3: Cook the garlic and wilt the spinach
While the mushrooms roast, set a large skillet over medium heat. Add the remaining 1 1/2 tbsp olive oil. Add the minced garlic and cook for 30–45 seconds, stirring constantly, just until fragrant (don’t let it brown).
Add the spinach in big handfuls, stirring as it wilts. Cook until all the spinach is fully wilted and tender, 2–3 minutes. Stir in the crushed red pepper flakes if using.
Transfer the spinach to a fine-mesh strainer. Press firmly with a spoon to remove as much liquid as possible (this step is key for a creamy filling, not a watery one). When cool enough to handle, squeeze again with clean hands, then roughly chop.
Step 4: Make the spinach-ricotta filling
In a medium bowl, combine the ricotta, Parmesan, Italian seasoning, and egg. Add the well-drained chopped spinach. Season with the remaining 1/4 tsp kosher salt and 1/4 tsp black pepper. Mix until evenly combined.
The filling should be thick and scoopable. If it seems loose, it almost always means the spinach needs a bit more squeezing.
Step 5: Fill the mushrooms and add sauce and cheese
Remove the mushrooms from the oven. Carefully pour off any liquid that collected on the baking sheet or inside the caps. Flip the caps gill-side down (so they’re like little bowls).
Divide the ricotta mixture evenly among the caps, mounding it slightly. Spoon about 1/4 cup marinara over each mushroom, then sprinkle the mozzarella evenly on top.
Step 6: Bake until bubbly and melty
Return the baking sheet to the oven and bake until the filling is hot and the cheese is melted, 12–15 minutes.
If you want a little browning on top, switch to broil on high for 1–2 minutes, watching closely so the cheese doesn’t burn.
Step 7: Toss the lemony salad and serve
In a large bowl, whisk together the olive oil, lemon juice, Dijon, honey, salt, and pepper until emulsified. Add the mixed greens, cucumber, and cherry tomatoes and toss until lightly coated.
Serve each stuffed portobello with a generous handful of lemony salad. Finish the mushrooms with chopped basil or parsley if you like.
Pro Tips
- Roast before stuffing: That first 10-minute roast drives off moisture so your mushrooms don’t turn soupy after filling.
- Squeeze the spinach very dry: The drier the spinach, the creamier and more cohesive the ricotta filling will be.
- Use whole-milk ricotta: It gives a richer, less grainy filling and holds up better in the oven.
- Control the salt: Marinara and Parmesan vary a lot. Taste the ricotta mixture (before adding the egg if you prefer) and adjust gently.
- Broil with caution: Mozzarella goes from golden to burnt quickly; stay nearby for the last minute.
Variations
- Add protein: Mix 1/2 cup (about 75 g) cooked, chopped Italian chicken sausage into the filling.
- Extra veggie version: Add 1/2 cup finely diced sautéed bell pepper or zucchini (cook and drain well) to the ricotta mixture.
- Spicy arrabbiata: Use spicy marinara and increase red pepper flakes to 1/2 tsp; finish with a drizzle of good olive oil.
Storage & Make-Ahead
Refrigerate: Store cooked stuffed mushrooms in an airtight container for up to 3 days. Keep salad and dressing separate.
Reheat: Warm on a baking sheet at 375°F (190°C) for 10–12 minutes until heated through (microwaving works, but the mushrooms will be softer).
Make-ahead: You can make the ricotta filling up to 24 hours ahead and refrigerate it. You can also roast the mushroom caps for the first 10 minutes, cool, and refrigerate; then stuff and bake when ready (add 2–4 minutes to the final bake if cold).
Nutrition (per serving)
Approximate, for 1 stuffed portobello plus salad: 430 calories, 26 g protein, 24 g fat, 28 g carbohydrates, 7 g fiber, 9 g sugar, 900 mg sodium.
