Cauliflower Au Gratin Recipe
Introduction
This Cauliflower Au Gratin is a comforting and cheesy side dish that combines tender roasted cauliflower and broccoli with a rich, creamy cheese sauce. Topped with a crunchy, flavorful crumb layer, it’s perfect for elevating any meal or enjoying on its own.

Ingredients
- 1 small head broccoli, cut into florets
- 1 small head cauliflower, cut into florets
- 4 tablespoons unsalted butter
- 1 small onion, chopped
- 2 large cloves of garlic, minced
- 1/4 cup flour
- 1 1/2 cups milk
- 3/4 cup low sodium chicken broth
- 2 1/4 cups shredded white cheddar
- Pinch of nutmeg
- Salt & pepper to taste
Crumb Topping
- 20 Ritz crackers
- 1 teaspoon dried oregano
- 1/2 teaspoon onion powder
- 3 tablespoons melted butter
Instructions
- Step 1: Preheat the oven to 400 degrees. Spray a large baking dish with nonstick baking spray. Spread the broccoli and cauliflower florets evenly in the dish and bake for 15 minutes, or until they start to turn lightly browned.
- Step 2: In a large skillet over medium heat, melt the butter. Add the chopped onion and cook for 5 minutes until softened. Stir in the minced garlic and cook for 30 seconds more.
- Step 3: Whisk in the flour and cook for 90 seconds, stirring constantly to form a roux. Slowly whisk in the milk and chicken broth, alternating between the two, until incorporated and smooth.
- Step 4: Reduce heat to low and add the shredded cheddar cheese. Whisk frequently until the cheese has fully melted and the sauce is creamy. Stir in the pinch of nutmeg and season with salt and pepper to taste.
- Step 5: Pour the cheese sauce evenly over the roasted broccoli and cauliflower in the baking dish.
- Step 6: In a food processor, crush the Ritz crackers until they are coarse crumbs. Add the dried oregano, onion powder, and melted butter, then pulse a few times to combine. Sprinkle this crumb topping evenly over the cheese sauce.
- Step 7: Bake for 25 to 30 minutes, or until the topping is lightly golden brown and crispy. Remove from oven and let cool slightly before serving.
Tips & Variations
- You can use all cauliflower, all broccoli, or any combination you prefer for this dish.
- Make sure to dry the florets well after washing to ensure they roast instead of steam.
- Nonstick cooking spray helps with easy cleanup of the casserole dish.
- Use good quality cheddar cheese for the best flavor and texture.
- If you don’t have Ritz crackers, substitute fresh ground croutons or breadcrumbs for the topping.
- For extra flavor, reserve some cheddar and sprinkle it on top of the crumb mixture before baking.
- Try mixing in other cheeses like Gouda, Gruyere, or Monterey Jack to customize the taste.
Storage
Store any leftovers covered in the refrigerator for up to 3 days. To reheat, warm portions gently in the oven at 350 degrees until heated through to preserve the crispy topping. Avoid microwaving to keep the texture intact.
How to Serve

Serve this delicious recipe with your favorite sides.
FAQs
Can I make this dish vegetarian?
Yes! Simply substitute vegetable broth for the chicken broth to keep it vegetarian.
Can I prepare this ahead of time?
Yes, you can assemble the dish up to the point of baking, cover it, and refrigerate for up to 24 hours. Bake it when ready, adding a few extra minutes if baking from cold.
PrintCauliflower Au Gratin Recipe
This Cauliflower Au Gratin is a comforting and creamy baked vegetable dish featuring roasted cauliflower and broccoli florets smothered in a smooth white cheddar cheese sauce, topped with a crunchy, flavorful cracker crumb topping. Perfect as a hearty side or a vegetarian main, this recipe blends roasting and baking techniques for maximum flavor and texture.
- Prep Time: 15 minutes
- Cook Time: 45 minutes
- Total Time: 1 hour
- Yield: 6 servings 1x
- Category: Side Dish
- Method: Baking
- Cuisine: American
- Diet: Vegetarian
Ingredients
Vegetables
- 1 small head broccoli, cut into florets
- 1 small head cauliflower, cut into florets
Cheese Sauce
- 4 tablespoons unsalted butter
- 1 small onion, chopped
- 2 large cloves garlic, minced
- 1/4 cup flour
- 1 1/2 cups milk
- 3/4 cup low sodium chicken broth
- 2 1/4 cups shredded white cheddar cheese
- Pinch of nutmeg
- Salt and pepper to taste
Crumb Topping
- 20 Ritz crackers
- 1 teaspoon dried oregano
- 1/2 teaspoon onion powder
- 3 tablespoons melted butter
Instructions
- Preheat and Roast Vegetables: Preheat your oven to 400°F (200°C) and lightly grease a large baking dish with nonstick baking spray. Place the broccoli and cauliflower florets in the dish and bake for 15 minutes, or until they are just lightly browned. This step helps to develop flavor by roasting instead of steaming.
- Prepare the Cheese Sauce: While the vegetables roast, melt the butter in a large skillet over medium heat. Add the chopped onion and cook for about 5 minutes until softened. Stir in the minced garlic and cook for an additional 30 seconds. Gradually whisk in the flour and cook for 90 seconds while whisking continuously to eliminate raw flour taste. Slowly add the milk and chicken broth alternately, whisking constantly to create a smooth mixture. Reduce heat to low, then add the shredded cheddar cheese a handful at a time, whisking until fully melted and the sauce is creamy. Season with nutmeg, salt, and pepper to taste.
- Make the Crumb Topping: In a food processor, pulse the Ritz crackers until finely crushed. Add the dried oregano, onion powder, and melted butter, then pulse a few times until well combined and crumbly.
- Assemble and Bake: Pour the smooth cheese sauce evenly over the roasted broccoli and cauliflower in the baking dish. Sprinkle the cracker crumb topping evenly on top of the cheese layer. Place the casserole back into the oven and bake for 25 to 30 minutes, or until the topping is light golden brown and crispy.
Notes
- This recipe is flexible: use all cauliflower, all broccoli, or any mix you prefer.
- Dry the cut florets thoroughly to prevent steaming and ensure proper roasting.
- Use nonstick spray to grease the baking dish for easy cleanup.
- Load the casserole dish onto the middle rack of a preheated oven for even baking.
- Quality cheddar cheese greatly enhances flavor – choosing a good one is worth it.
- If you don’t have Ritz crackers, substitute with fresh ground croutons or bread crumbs.
- For extra flavor, sprinkle some reserved cheddar cheese on top of the crushed cracker topping before baking.
- Try alternate cheeses like Gouda, Gruyere, or Monterey Jack for different flavor profiles.
- Cooking this dish is a fun and relaxing way to experiment with vegetables and cheese.
Keywords: Cauliflower au gratin, cauliflower recipe, broccoli cauliflower gratin, cheesy vegetable bake, baked cauliflower, vegetarian side dish, comfort food, creamy cheese sauce, cracker topping

