Cauliflower Casserole

This Creamy Cauliflower Casserole features roasted cauliflower, mushrooms, and a rich cheese sauce, baked to perfection for a comforting, savory dish that's perfect for any occasion.

Cauliflower is often seen as a humble vegetable, but when paired with a creamy cheese sauce and roasted to perfection, it becomes the star of the show. This Cauliflower Casserole recipe, loaded with tender roasted cauliflower, earthy mushrooms, and a decadent cheese sauce, takes comfort food to a whole new level. Whether you're a fan of vegetables or just looking for a satisfying, cheesy dish, this casserole is sure to please you.

Below, I'll walk you through the steps to make this delicious dish and offer helpful tips, storage advice, recipe variations, and explain why this casserole is such a great side dish for any meal.

Video Tutorial

Ingredients for this Cauliflower Casserole

Roasted Cauliflower and Mushrooms:

• cauliflower florets (about 1 large cauliflower head)
• mushrooms, sliced
• olive oil
• salt
• black pepper
• garlic powder

Cheese Sauce:

• unsalted butter
• all-purpose flour
• whole milk
• salt
• nutmeg powder
• cheddar cheese, grated
• Gruyère cheese, grated

Topping:

• cheddar cheese, grated
• Gruyère cheese, grated

How to make this Cauliflower Casserole

1. Prepare and Roast the Vegetables. Preheat your oven to 430°F. Toss the cauliflower florets and sliced mushrooms in olive oil, salt, pepper, and garlic powder. Spread the vegetables on a baking sheet and roast for 25-30 minutes or until golden brown and tender. Once done, set aside to cool slightly.

2. Make the Cheese Sauce. In a medium saucepan, melt the butter over medium heat. Add the flour and whisk for about 1 minute to create a roux. Gradually whisk in the milk, stirring constantly to avoid lumps. Cook for about 3-5 minutes until the sauce thickens. Stir in the salt, nutmeg, and grated cheeses, allowing them to melt into a smooth sauce.

3. Combine and Bake. Reduce the oven temperature to 390°F. In a baking dish, combine the roasted cauliflower and mushrooms with the cheese sauce. Sprinkle with the remaining grated cheddar and Gruyère cheese.

4. Final Bake. Bake for 15-20 minutes, or until the top is bubbly and golden brown. Serve hot, and enjoy the cheesy, savory goodness!

Helpful tips & tricks

• Roasting Vegetables. Roasting cauliflower and mushrooms brings out their natural sweetness and depth of flavor. Be sure to spread them in a single layer on your baking sheet to ensure even roasting. If your sheet is too crowded, the vegetables will steam rather than roast, resulting in a soggier dish.
• Cheese Sauce. When making the cheese sauce, it's essential to whisk constantly after adding the milk to prevent lumps. If the sauce becomes too thick, you can always add a splash of more milk to reach the desired consistency.
• Even Cheese Distribution. To ensure that the sauce and cheese coat every piece of cauliflower and mushroom evenly, give the casserole a good toss before adding the final cheese topping. This helps distribute the sauce throughout the dish for a creamy bite every time.
• Preventing a Watery Casserole. Mushrooms can release a lot of moisture as they cook. To combat this, ensure that you roast them thoroughly, allowing excess moisture to evaporate. If you notice a lot of liquid in your casserole after baking, simply let it sit for a few minutes to reabsorb any liquid.

How to store and reheat

• Storing: Allow the casserole to cool completely before storing. Transfer it to an airtight container and store it in the refrigerator for up to 3-4 days. If you plan to keep it longer, you can freeze the casserole for up to 3 months. Make sure to wrap it tightly in plastic wrap or foil and place it in a freezer-safe container.
• Reheating: To reheat, simply place the casserole in a preheated oven at 350°F for about 15-20 minutes or until hot and bubbly. If you’re reheating from frozen, it's best to thaw it in the fridge overnight and then bake as usual. For individual servings, you can microwave for 1-2 minutes, depending on the size of the portion.

Recipe Variations

• Add Protein: Want to make this a full meal? Add cooked chicken, bacon, or sausage to the casserole for a protein boost. Simply toss the protein with the cauliflower and mushrooms before mixing with the cheese sauce.
• Spicy Kick: If you enjoy a little heat, add a pinch of cayenne pepper or red pepper flakes to the cheese sauce. This adds a nice contrast to the richness of the cheese and the earthiness of the cauliflower and mushrooms.
• Different Cheeses: While the combination of Cheddar and Gruyère works beautifully in this recipe, feel free to experiment with other cheeses. Gouda, mozzarella, sharp cheddar cheese,  Parmesan cheese, or even a bit of blue cheese can add a unique twist to the flavor profile.
• Make it Vegan: To make this casserole vegan-friendly, swap the dairy ingredients for plant-based alternatives. Use vegan butter, flour, and non-dairy milk like oat or almond milk. For the cheese sauce, look for vegan cheese options that melt well, or make a cashew-based cheese sauce for a creamy texture.
• Herb Infusion: Fresh or dried herbs like thyme, rosemary, green onions, or sage can elevate the flavors of this dish. Toss a few sprigs of fresh herbs into the roasting vegetables for an extra burst of flavor.

What to serve this Cauliflower Casserole with

• Chicken. The savory, juicy flavors of chicken complement the rich, cheesy casserole. Try my Easy Chicken Kebabs, Quick Parmesan Chicken, or Spinach Stuffed Chicken Breast. Steak or Pork Chops
• Steak or Pork Chops. A perfectly cooked steak or a pan-seared pork chop makes for a hearty pairing. Try my Air Fryer Pork Chops.
• Baked Salmon or Fish Fillets. For a lighter option, baked salmon or other flaky white fish like cod or halibut offer a nice contrast to the rich flavors of the casserole. Try my Baked Cod, Easy Salmon Patties, or Cajun Salmon.
•  A Fresh Green Salad. A crisp green salad with a tangy vinaigrette provides a refreshing contrast to the creamy casserole. Try my Chickpea Iceberg Salad, Spring Mix Salad, or Kale Salad with Quinoa. 

I hope you try my Cauliflower Casserole, friends!  It is a crowd-pleasing casserole dish that combines the best of both worlds: the comfort of a cheesy, creamy dish with the health benefits of cauliflower and mushrooms. It’s easy to make, versatile, and perfect for any occasion. Whether you stick to the original recipe or try out some of the variations, you’re guaranteed a dish that will be a hit with family and friends. 

If you make this recipe, please let me know! Leave a comment, rate it, or drop an email. The printable recipe and nutrition information are located in the recipe card below.

More tasty cauliflower recipes to try:

• Cauliflower Fritters
• Cauliflower Alfredo Sauce
• Cauliflower Steaks
• Steamed Cauliflower