This super simple cauliflower and potato bake is a great prep-ahead recipe that pairs well with just about anything. A cheesy sauce, seasoned with mustard, onion, and garlic, coats cooked cauliflower and potatoes. It makes a wonderful side dish for St. Patrick’s Day, Easter, Thanksgiving, Christmas, or a weeknight meal with the family.
Reader note: This post was originally published in March 2021. It was updated with new photos and some ingredient changes in November 2023.
I’m really crushing on this cauliflower and potato bake. It’s so easy and although it’s not groundbreaking in any way, there’s something about the simplicity of a veggie casserole that never disappoints.
Cauliflower and potatoes prove to be a delicious pair. They really shine with a well-seasoned cheesy sauce, and together they’re a source of healthy carbohydrates and non-starchy vegetables. My husband Will particularly liked that the cauliflower provides a different texture and flavor that breaks up the mundanity of the potatoes.
I encourage you to try this recipe in place of your regular holiday potatoes au gratin and see what your family thinks! Round out the meal with a source of protein, like Thanksgiving turkey, Easter or Christmas ham, St. Paddy’s Day corned beef, or lenten Friday fish, to make a balanced dinner. Plus, this dish makes enough to feed the whole family and can be prepped ahead of time.
Ingredients and Substitutions
- Cauliflower: Use a medium or large head of cauliflower, about 6 cups worth of florets. You can substitute frozen cauliflower too! Since you’ll be boiling the veggies before baking the casserole, you don’t have to worry about frozen veggies being too soggy in there.
- Potatoes: Yukon gold are the best option for a cauliflower and potato bake. Swap in Russet potatoes if that’s what you prefer, but I don’t recommend many other types. You want to have the right starch content.
- Butter: Use unsalted. You could technically substitute extra virgin olive oil, but butter provides a really rich flavor.
- Flour: I used all purpose flour, but I imagine a gluten-free 1:1 substitute would work well.
- Milk: You can use milk with any fat content. If you want to cut down the milk a little, substitute part of it with more broth.
- Vegetable broth: Chicken broth can also be substituted. Use low sodium so the dish doesn’t get too salty. If using regular, omit the added salt.
- Onion powder, garlic powder, salt, and pepper: Use these to season the sauce. If you want to use fresh garlic, use 2 cloves.
- Dijon mustard: This adds great flavor to the sauce. Sub whole grain mustard if that’s what you have.
- Parmesan and sharp cheddar cheese: I add a little parmesan to the sauce, but if you don’t have it, just use all cheddar. It’ll be great either way! You could also sub gruyere or another cheese.
- Chives: Top the dish with chives or any herb you have on hand that you think would taste good.
How to Make Cauliflower and Potato Bake
The full recipe card, including ingredient quantities and all of my expert tips, is at the bottom of the post. Here’s a preview of how to make it with photos to guide you in the kitchen.
Cut the cauliflower into florets. Cut the potatoes into ½-inch slices.
Place the potatoes in a large pot, cover with salted water and bring to a boil. Once boiling, add the cauliflower florets. Cook for 8 to 10 minutes. Drain.
Melt the butter in a saucepan. Whisk in the flour.
Slowly pour in the milk and broth, whisking constantly, until the sauce thickens. Turn off the heat. Stir in the seasonings and cheese.
Place the cooked cauliflower and potatoes in a greased 9×13 dish. Pour the sauce over them.
Top with the rest of the cheese and the sliced chives. Bake until the sauce is bubbly and the cheese is slightly browned. Turn on the broiler for a couple of minutes at the end to brown the cheese. Remove from the oven and let cool for 5 to 10 minutes before serving.
Make Ahead Tips
Cauliflower and potato bake is very easy to prep ahead of time to pop in the oven when you’re ready to bake it. Just follow the instructions up until you put the dish in the oven, then cover the uncooked bake with a lid, foil, or plastic wrap. Keep it in the fridge for up to a day before baking.
Storage and Reheating
For large portions of leftovers, keep them in the dish and reheat in the oven at 350 degrees F for about 10 to 15 minutes. Cover the dish with foil to prevent the cheese from burning. You can use this same method of reheating if you baked the casserole in advance for a holiday dinner.
Smaller amounts of leftovers can be stored in an airtight container in the fridge for up to 5 days. Reheat in the oven or in the microwave until warmed through.
More Healthy Cauliflower and Potato Recipes
If you like this cheesy cauliflower and potato bake, check out the Vegan Potato Salad Recipe with Fresh Dill, Healthy Crockpot Mashed Potatoes with Arugula, and Baked Whole Cauliflower with Cheese. You may also enjoy the Turnip and Beet Gratin with Gruyere, another cheesy layered vegetable bake.
I’d love to hear how you like this recipe! Rate/review using the stars on the recipe card or in the comments, and follow the Veg World on YouTube, Instagram, Facebook, and Pinterest. Looking for something totally different? Browse the recipe library.
Easy Cheesy Cauliflower and Potato Bake
- 1 pound Yukon gold potatoes - sliced into ½-inch rounds
- 1 medium head cauliflower - cut into florets, about 5 to 6 cups
- 4 tablespoons unsalted butter
- ¼ cup all purpose flour
- 1.5 cups milk - any fat content
- ½ cup low sodium vegetable broth
- 1 tablespoon Dijon mustard
- 1 teaspoon onion powder
- 1 teaspoon garlic powder
- ¼ teaspoon salt
- ¼ teaspoon freshly ground black pepper
- ¼ cup shredded parmesan cheese
- 1.25 cups shredded sharp cheddar cheese - divided
- ¼ cup chopped fresh chives
- Preheat the oven to 375 degrees F. Grease a 9×13 rectangular baking dish and set aside.
- Place the sliced potatoes in a large pot and cover with salted water. Make sure you cover the potatoes by at least a couple of inches, so that there is room in the pot for the cauliflower to cook too. Bring the pot with the potatoes to a boil, add in the cauliflower florets, and cook for 8 to 10 minutes until the potatoes are soft but not falling apart. Drain.
- While the veggies are cooking, melt the butter in a saucepan over medium heat. Whisk in the flour to form a paste. Slowly pour in the milk followed by the broth, whisking constantly. Cook for a few more minutes, whisking often, until the sauce thickens. Stir in the Dijon mustard, onion powder, garlic powder, salt, and pepper.
- Turn off the heat on the sauce. Stir the parmesan cheese and ¾ cup of the cheddar cheese into the sauce.
- Transfer the cooked veggies to the greased baking dish and spread out in an even layer. Pour the cheese sauce over the veggies.
- Sprinkle the casserole with the rest of the cheddar cheese and the sliced chives. I like to use kitchen shears to quickly cut the chives over the casserole.
- Bake for 20 to 25 minutes until the sauce is bubbling and the cheese is slightly browned. Flip the broiler on and finish baking the dish for 2 to 3 more minutes until the cheese is fully browned.
- Remove from the oven and garnish with more fresh chives as desired. Let it sit for 5 to 10 minutes before serving.
- Leave a rating or review by tapping the stars on this recipe card (above) or in the comments section (at the end of the post)!
- Swap rosemary, parsley, or thyme for the chives if you have those on hand.
- To make ahead of time, follow the instructions until putting the dish in the oven. Cover the uncooked dish with a lid, foil, or plastic wrap, and keep in the fridge for up to a day until you are ready to bake it.
- If you are fully baking the dish ahead of time for a holiday dinner, reheat in the baking dish at 350 degrees F for about 10 to 15 minutes until warmed through. You may want to cover it with foil to keep the cheese from getting too brown.
- Store leftovers in an airtight container in the fridge for up to 5 days.