Quick Recipe Version (TL;DR)
Quick Ingredients
- 1 large cauliflower (about 2 1/2 lb / 1.1 kg), cut into 1 1/2-inch florets
- 2 tbsp olive oil
- 1 1/4 tsp kosher salt, divided; 1/2 tsp black pepper, divided
- 4 tbsp unsalted butter, divided
- 3 tbsp all-purpose flour
- 2 cups whole milk
- 2 tsp Dijon mustard
- 2 cloves garlic, finely grated
- 1/4 tsp smoked paprika
- 8 oz sharp cheddar, shredded (about 2 cups)
- 1 oz Parmesan, finely grated (about 1/2 cup), divided
- 1 cup panko breadcrumbs
- 2 tbsp chopped parsley (optional)
Do This
- 1) Heat oven to 425°F. Toss cauliflower with olive oil, 3/4 tsp salt, and 1/4 tsp pepper; roast 20 minutes.
- 2) Mix panko + 2 tbsp melted butter + 1/4 cup Parmesan + pinch salt; set aside.
- 3) Lower oven to 375°F. Make cheese sauce: melt 2 tbsp butter, whisk in flour 1 minute.
- 4) Slowly whisk in milk; simmer 3–5 minutes until thick. Stir in mustard, garlic, paprika.
- 5) Off heat, melt in cheddar + remaining Parmesan; taste and salt as needed.
- 6) Toss roasted cauliflower with cheese sauce; spread in a greased 9×9-inch (or 2.5-quart) baking dish.
- 7) Top with breadcrumbs; bake 15 minutes until bubbly and golden. Rest 5 minutes, then serve.
Why You’ll Love This Recipe
- It delivers real mac-and-cheese vibes with roasted cauliflower standing in for pasta.
- The cheddar sauce is rich and creamy, but mustard and garlic keep it sharp and savory (not flat).
- A crunchy panko-Parmesan topping gives you that baked-casserole texture you crave.
- It’s easy enough for weeknights, but impressive on a holiday table.
Grocery List
- Produce: 1 large cauliflower, garlic, parsley (optional)
- Dairy: unsalted butter, whole milk, sharp cheddar cheese, Parmesan cheese
- Pantry: olive oil, all-purpose flour, Dijon mustard, panko breadcrumbs, smoked paprika, kosher salt, black pepper
Full Ingredients
Roasted Cauliflower
- 1 large head cauliflower (about 2 1/2 lb / 1.1 kg), cut into 1 1/2-inch florets
- 2 tbsp olive oil
- 3/4 tsp kosher salt
- 1/4 tsp freshly ground black pepper
Cheddar Cheese Sauce
- 2 tbsp unsalted butter
- 3 tbsp all-purpose flour
- 2 cups whole milk
- 2 tsp Dijon mustard
- 2 cloves garlic, finely grated (or pressed)
- 1/4 tsp smoked paprika
- 1/2 tsp kosher salt, plus more to taste
- 1/4 tsp freshly ground black pepper
- 8 oz sharp cheddar cheese, shredded (about 2 cups, packed)
- 1/4 cup finely grated Parmesan cheese (about 1/2 oz), for the sauce
Crunchy Breadcrumb Topping
- 1 cup panko breadcrumbs
- 2 tbsp unsalted butter, melted
- 1/4 cup finely grated Parmesan cheese (about 1/2 oz)
- 1/4 tsp kosher salt
- 2 tbsp chopped fresh parsley (optional, for a fresh finish)
Step-by-Step Instructions
Step 1: Preheat the oven and prep the baking dish
Arrange a rack in the middle of the oven and preheat to 425°F. Lightly grease a 9×9-inch baking dish (or a similar 2.5-quart casserole dish) with a little butter.
Cut the cauliflower into 1 1/2-inch florets. Try to keep them fairly even so they roast at the same rate.
Step 2: Roast the cauliflower for deep flavor
On a large rimmed sheet pan, toss the cauliflower florets with 2 tbsp olive oil, 3/4 tsp kosher salt, and 1/4 tsp black pepper. Spread into a single layer (crowding causes steaming, not roasting).
Roast at 425°F for 20 minutes, stirring once halfway through, until the cauliflower is tender-crisp and nicely browned on the edges.
Step 3: Mix the crunchy breadcrumb topping
While the cauliflower roasts, stir together 1 cup panko, 2 tbsp melted butter, 1/4 cup Parmesan, and 1/4 tsp kosher salt in a small bowl. The crumbs should look evenly coated and slightly clumpy.
Set aside so it’s ready to sprinkle on right before baking.
Step 4: Lower the oven temperature for baking
When the cauliflower comes out, reduce the oven temperature to 375°F. This keeps the casserole from scorching while the sauce bubbles and the topping turns golden.
Leave the cauliflower on the pan for a minute while you start the sauce.
Step 5: Build a smooth, thick cheese sauce
In a medium saucepan over medium heat, melt 2 tbsp unsalted butter. Whisk in 3 tbsp flour and cook, whisking constantly, for 1 minute. This cooks out the raw flour taste and forms a roux.
Slowly whisk in 2 cups whole milk. Keep whisking until smooth, then bring to a gentle simmer. Cook for 3 to 5 minutes, whisking often, until the sauce thickens enough to coat the back of a spoon.
Stir in 2 tsp Dijon mustard, 2 finely grated garlic cloves, 1/4 tsp smoked paprika, 1/2 tsp kosher salt, and 1/4 tsp black pepper.
Step 6: Melt in the cheese and coat the cauliflower
Turn the heat to low. Add the shredded sharp cheddar a handful at a time, stirring until melted before adding more. Stir in 1/4 cup Parmesan for extra savory depth.
Taste the sauce and adjust salt if needed (cheese brands vary a lot in saltiness).
Add the roasted cauliflower to a large mixing bowl (or keep it on the sheet pan if it’s roomy), pour the cheese sauce over, and gently toss until every floret is coated.
Step 7: Assemble, bake until bubbly, and serve
Spoon the cheesy cauliflower into the prepared baking dish and spread into an even layer. Sprinkle the breadcrumb topping evenly over the surface.
Bake at 375°F for 15 minutes, until the edges are bubbling and the topping is golden brown. If you want extra color, broil on high for 1 to 2 minutes (watch closely; panko can go from golden to burnt quickly).
Let the casserole rest for 5 minutes to thicken slightly, then finish with chopped parsley (optional) and serve warm.
Pro Tips
- Shred your own cheddar: Pre-shredded cheese often contains anti-caking agents that can make sauces grainy.
- Roast, don’t steam: Use a large sheet pan and spread cauliflower in a single layer for browning and flavor.
- Keep the sauce gentle: Once the cheese goes in, use low heat to prevent a broken or oily sauce.
- Want it thicker? Simmer the milk-and-roux mixture an extra 1–2 minutes before adding cheese.
- Broil carefully: If you broil for color, do it at the very end and stay nearby.
Variations
- Spicy jalapeño cheddar: Add 1 minced jalapeño (seeded) to the sauce with the garlic, and add 1/8 tsp cayenne.
- Broccoli-cauliflower blend: Replace 1/2 of the cauliflower with 1 1/4 lb broccoli florets; roast together.
- Extra “mac” vibe: Stir 2 tbsp cream cheese into the sauce with the cheddar for an even silkier texture.
Storage & Make-Ahead
Refrigerate: Cool completely, cover, and refrigerate for up to 4 days.
Reheat: For best texture, reheat in a 375°F oven for 15–20 minutes until hot and bubbly. Microwave reheating works, but the topping will soften (you can re-crisp under the broiler for 1 minute).
Make-ahead: Roast the cauliflower and make the cheese sauce up to 1 day ahead. Store separately in the fridge. Rewarm the sauce gently on the stove with a splash of milk, assemble, top with breadcrumbs, and bake as directed.
Freeze: Freezing is possible, but the sauce can separate slightly. If you do freeze, freeze baked portions airtight for up to 2 months, thaw overnight in the fridge, and reheat in the oven.
Nutrition (per serving)
Approximate, based on 6 servings: 390 calories, 26 g fat, 20 g carbs, 19 g protein, 4 g fiber, 820 mg sodium.
