This Cheesy Cauliflower Casserole is easy to make with frozen or fresh cauliflower and loads of good things in only 30 minutes. Everybody will love it, but it's perfect for gluten-free, low-carb, and keto diets.

Jump To:
This cheese cauliflower bake is a delicious vegetable side dish with tender mashed cauliflower in a flavorful cheesy sauce using all-natural products.
😊Why you will love this recipe
- A great vegetable side dish for potato lovers.
- It fits well in gluten-free, low-carb, and keto diets.
- It only takes 30 minutes to complete and is easy enough for novice cooks.
- It can be made ahead and stored.
- Easy to modify by using a different cheese or adding flavor with your favorite spices and herbs.
- Perfect for casual or fancy meals.
- The whole family, including the kids, will love this cauliflower casserole.
I was initially inspired by my Cheesy Potatoes with Real Potatoes when we wanted a smaller non-potato casserole side dish over ten years ago and repeated many times since.
👨🍳How to Make Cheesy Cauliflower Casserole
- Preheat oven to 375° convection or 400° conventional.
- Cook cauliflower florets in the microwave.
- Slice green onions.
- Mash the cauliflower with a potato masher. A food processor can be used, but you want some texture, not creamy.
- Add cheddar cheese, sour cream, green onion, salt, and pepper. Add bacon if using. Stir well.
- Mix well and pour the mixture into a prepared baking dish.
- Bake until the top is browned—about 20 minutes.
- Let set for 5 minutes before serving.
The Cauliflower
This is a perfect frozen cauliflower recipe—no need to thaw the cauliflower. Just cook it according to the package instructions.
The recipe is for one pound of florets, but bags have gotten smaller. Now, most frozen cauliflower comes in 12 oz. bags. If you use 12 oz., please adjust other ingredients.
You can use fresh cauliflower. One medium head of cauliflower (about 2 pounds) will trim out to about 1 pound of well-trimmed florets.
You should precook the fresh cauliflower in a microwave or boil it.
For the Microwave: Place the cauliflower florets in a large microwave-safe bowl with a couple of tablespoons of water. Cover the bowl loosely but not tightly. Cook on high until tender, 4 to 5 minutes, and drain.
❓FAQs
Yes. You can freeze cauliflower casserole after assembly but before cooking or freeze leftovers after cooking sealed airtight for three months.
To reheat or cook, thaw completely.
Sealed airtight in the refrigerator for three days. Reheating in the microwave, but we prefer the oven.
📖 Low-Carb Recipes
Low Carb Parmesan-Sesame Crackers
This recipe is listed in these categories. See them for more similar recipes.
🖼️Step-by-Step Photo Instructions
Preheat the oven to 375° convection or 400° conventional.
Use frozen cauliflower and cook 1 pound of cauliflower florets in the microwave. Follow the instructions on the package.
For Fresh Cauliflower: One medium head of cauliflower (about 2 pounds) will trim out to about 1 pound of well-trimmed florets.
Place the fresh cauliflower florets in a large microwave-safe bowl with a couple of tablespoons of water. Cover the bowl loosely but not tightly. Cook on high until tender, 4 to 5 minutes, then drain.
Slice 3 green onions.
Prepare a 6 by 9 baking dish or a 9 by 10 Corningware casserole dish with PAM cooking spray.
Move cauliflower to the large mixing bowl and mash with a potato masher or forks. You could also use a mixer or food processor, but you are NOT trying to cream this. Add sharp cheddar cheese, sour cream, green onion, salt, and black pepper. Bacon is optional.
Mix well and pour the mixture into a prepared baking pan. It may be refrigerated or cooked now.
Cook in the oven until the top is browned—about 20 minutes. Let sit for 5 minutes before serving.
Recipe
Cheesy Cauliflower Casserole
Ingredients
- 1 lb frozen cauliflower
- 1 cup sour cream
- 1 cup sharp cheddar cheese
- 3 green onions - sliced thin
- ½ teaspoon salt
- ¼ teaspoon black pepper - coarse ground
- 3 slices bacon - optional. Cooked and crumbled.
Instructions
- Preheat the oven to 375° convection or 400° conventional.
- Use frozen cauliflower and cook 1 pound of cauliflower florets in the microwave. Follow the instructions on the package. For Fresh Cauliflower: One medium head of cauliflower (about 2 pounds) will trim out to about 1 pound of well-trimmed florets.Place the fresh cauliflower florets in a large microwave-safe bowl with a couple of tablespoons of water. Cover the bowl loosely but not tightly. Cook on high until tender, 4 to 5 minutes, then drain.
- Prepare a 6 by 9 baking dish or a 9 by 10 Corningware casserole dish with PAM cooking spray.
- Slice 3 green onions.
- Move cauliflower to the large mixing bowl and mash with a potato masher or forks. You could also use a mixer or food processor, but you are NOT trying to cream this. Add sharp cheddar cheese, sour cream, green onion, salt, and black pepper. Bacon is optional.
- Mix well and pour the mixture into a prepared baking pan. It may be refrigerated or cooked now.
- Cook in the oven until the top is browned—about 20 minutes. Let sit for 5 minutes before serving.
Your Own Private Notes
Recipe Notes
Pro Tips
- Make it "loaded" by adding 3 slices of cooked and crumbled bacon.
- It reheats well in a microwave, but we prefer the oven.
- Pan size. I usually use a 7 X 10 Corning Ware dish. A 6X9 or an 8 X 8 would be good, or anything in about that size range.
- Since this was originally published, many bags of frozen cauliflower have "shrunk" to 12 oz from 1 pound. The recipe will need to be decreased by 25% if that is what you have. Cooking time will be about the same.
To adjust the recipe size:
You may adjust the number of servings in this recipe card under servings. This does the math for the ingredients for you. BUT it does NOT adjust the text of the instructions. So you need to do that yourself.
Nutrition Estimate
© 101 Cooking for Two, LLC. All content and photographs are copyright protected by us or our vendors. While we appreciate your sharing our recipes, please realize copying, pasting, or duplicating full recipes to any social media, website, or electronic/printed media is strictly prohibited and a violation of our copyrights.
Editor's Note: Originally Published February 25, 2010. Updated with expanded options, refreshed photos, and a table of contents to help navigation.
Jan M
This was easy and quick to prepare; I also appreciated the note provided as to the point it could be prepared ahead of time and baked later. I halved the recipe and there was still enough for 4 servings. However, I'm sorry to say we did not enjoy the taste of the sour cream at all. The extra bacon and cheese I added did nothing to cover up the sour cream taste. Some day, I may try it with yogurt as others have suggested, or cream cheese, but as is it just did not work for us.
Sally
This is delicious and I make it a lot. I often don't have green onions so I use yellow onion or dried shallots. Easy to make variations. Sometimes we eat it as a side dish and sometimes as a main dish. Tonight I added 2 cups of leftover chili and maybe 3/4 cup of leftover corn. Added extra cheese on the top.