Cheesy Cauliflower Broccoli Gratin (Print version)

A creamy baked dish with tender cauliflower and broccoli in a rich cheese sauce and crispy topping.

# Ingredient List:

→ Vegetables

01 - 1 medium head cauliflower, cut into florets (approximately 1.3 lbs)
02 - 1 medium head broccoli, cut into florets (approximately 0.9 lbs)

→ Cheese Sauce

03 - 2 tablespoons unsalted butter
04 - 2 tablespoons all-purpose flour (gluten-free flour for GF option)
05 - 1 ½ cups whole milk
06 - 1 cup grated sharp cheddar cheese
07 - ½ cup grated Gruyère or Swiss cheese
08 - ½ teaspoon Dijon mustard
09 - ¼ teaspoon freshly grated nutmeg
10 - Salt and freshly ground black pepper, to taste

→ Topping

11 - ½ cup grated Parmesan cheese
12 - ½ cup fresh breadcrumbs (use gluten-free for GF option)
13 - 1 tablespoon olive oil

# How To Make It:

01 - Preheat oven to 400°F. Lightly grease a 2-quart baking dish.
02 - Bring a large pot of salted water to a boil. Add cauliflower and broccoli florets and cook for 3 to 4 minutes until just tender. Drain thoroughly and set aside.
03 - In a medium saucepan over medium heat, melt butter. Whisk in flour and cook, stirring constantly, for 1 minute.
04 - Gradually pour in milk while whisking until smooth and slightly thickened, about 3 to 4 minutes. Remove from heat and stir in cheddar, Gruyère, Dijon mustard, nutmeg, salt, and pepper until cheeses are fully melted.
05 - Place drained cauliflower and broccoli evenly in the prepared baking dish. Pour cheese sauce over the vegetables.
06 - Combine Parmesan, breadcrumbs, and olive oil in a small bowl. Evenly sprinkle this mixture over the gratin.
07 - Bake for 25 to 30 minutes until the topping is golden and the gratin is bubbling.
08 - Allow the gratin to rest for 5 minutes before serving.

# Expert Advice:

01 -
  • This gratin feels like sharing a secret comfort food that disguises healthy veggies in gooey, irresistible cheese.
  • It became a favorite because it’s quick to assemble yet impressively delicious, perfect for unexpectedly hungry guests.
02 -
  • Don’t overcook the vegetables; a slight firmness keeps the gratin’s texture delightful and avoids mushiness.
  • A touch of Dijon mustard brightens the cheese sauce more than you might expect, becoming the secret ingredient that changed how I make this every time.
03 -
  • Use freshly grated cheeses for better melt and flavor compared to pre-shredded varieties that contain anti-caking agents.
  • The combination of cheddar and Gruyère gives a depth that feels rich but not overpowering, making this queso harmony the star.