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This easy, cheesy Gluten Free Veggie Breakfast Casserole recipe is simple to make and totally satisfying. The tender Bisquick biscuit crust is topped with fresh vegetables and plenty of cheese for a delicious vegetarian brunch bake. Make it ahead for holidays or when you meal prep for busy weekdays!
We Love this Gluten Free Bisquick Breakfast Casserole
This savory breakfast bake is cheesy, creamy, and tasty! So much flavor and texture are packed into each bite. Like most gluten free casseroles for breakfast or brunch, this one does have some eggs. But instead of mixing those eggs with bread like a strata or potatoes like a hashbrown casserole, this one has a tender biscuit-like crust.
Yes, it’s just like a vintage Bisquick breakfast casserole, only this one is gluten free! So even if you had to give up gluten, you can still enjoy a classic dish you’ve always loved with the help of Gluten Free Bisquick. It’s also loaded with plenty of spinach, zucchini, and carrots, as well as cottage cheese and cheddar cheese to make it both creamy and cheesy.
My family especially loves it as breakfast for dinner. But it is perfect to make ahead for a holiday or weekend breakfast or brunch, or when you meal prep so you can reheat it for lunch or as a quick morning meal during the week.
Breakfast Casserole Ingredients
Let’s gather what we need to make this hearty casserole. Here is a quick overview, but you’ll want to read the recipe card for the full amounts.
For the veggie filling:
- Olive oil.
- Onion. Finely chopped, set aside some for the crust
- Carrots. Peeled and shredded.
- Zucchini. Quartered lengthwise, and slice about 1/4 in. thick
- Baby spinach. Chopped into small pieces
- Salt and pepper.
- Cottage cheese.
- Cheddar cheese. Sharp cheese gives the best flavor. You’ll want to shred this.
- Parmesan cheese. Grated.
- Egg plus egg whites.
- Dry mustard. In dishes with eggs and cheese, this is a simple seasoning that really makes the flavors pop.
For the gluten free biscuit crust:
- Gluten free pancake and baking mix. Tested with Gluten Free Bisquick. Lightly spoon it into your measuring cup and level it off, just like you would measure flour.
- Egg plus egg whites.
- Milk. Use any type of milk you prefer.
- Onion. Remember, you’ve chopped some extra when you were preparing the filling.
How to Make Veggie Breakfast Casserole
This is a really simple dish to assemble. Now that you have what you need, let’s get started. Make sure all of your ingredients are chopped and shredded. Get a skillet and some bowls, and coat a 9×13-inch baking dish with cooking spray or oil.
- Saute the veggies: Heat oil in a skillet over medium heat and saute onions until tender. Add carrots and zucchini and cook until the veggies are soft. Add the spinach and cover for several minutes until the spinach wilts. Set the mixture aside to cool.
- Make the filling and crust: While the veggies cool, mix together the crust ingredients and set it aside. In another bowl, combine the cheeses, eggs, and seasonings for the filling, then stir in the cooked vegetable mixture.
- Prepare and bake the casserole: Spread the crust mixture into the prepared baking dish. Spoon the filling mixture over the crust and spread evenly. Sprinkle additional parmesan cheese over the top. Pop your gluten free breakfast casserole in the oven at 350°F for 30-35 minutes or until it is cooked through and the top is golden brown and bubbly.
Tips for Success
Not gluten free? If you are not gluten free, you should still be able to use regular Bisquick in this recipe. I have not tested this exact version, but the original recipe this was based on (from a blog that no longer exists) used regular Bisquick.
Want to make it ahead? You can make this vegetarian breakfast casserole in advance too. It’s great for meal prep so you can easily reheat and enjoy a protein-packed meal even on busy mornings. See below for more information about storing and reheating it.
- Change the veggies. You can really use any kind of vegetable you like, including broccoli or cauliflower florets that are cut small, sliced mushrooms, or chopped bell peppers.
- Use your favorite cheese. Anything from Swiss to Monterey Jack to feta would change up the flavors.
- Add some meat. If you don’t want a vegetarian breakfast casserole, feel free to add some cubed ham or crumbled bacon to the veggie mixture.
Storing and Reheating Leftovers
Wrap the cooled casserole tightly or place slices into airtight storage containers. Keep them in the refrigerator for up to 3 to 4 days. You can reheat individual slices in the microwave or put the entire casserole back in the oven to heat it through. You may want to cover it with foil at first so it can warm up without getting too dark on top.
I would not recommend freezing this veggie breakfast casserole. The creamy veggie topping will get watery when frozen and thawed, making the Bisquick biscuit crust soggy. It would be safe to heat and eat, but probably not be enjoyable.
With all of the protein and veggies, this hearty breakfast bake doesn’t need much more to be a satisfying meal. When I make it as breakfast for dinner, I might add some Breakfast Sausage and a nice Tropical Fruit Salad. But there are many other ways to make it a meal!
- Vegetarian breakfast ideas. Blend up a Coconut Strawberry Banana Smoothie and serve it with some Vegan Sausage Patties.
- Holiday brunch sides. A creamy Waldorf Fruit Salad is a festive addition, as well as some Dill Breakfast Potatoes.
- Meal prep pairings. When you prepare this breakfast bake ahead, you can also assemble Make-Ahead Fruit Yogurt Parfaits then grab a Blended Iced Coffee on the way out the door.
Things You’ll Need
BAKING DISH: You’ll make this gluten free breakfast casserole in a 9×13 inch glass baking dish.
BAKING MIX: As mentioned, the biscuit crust is made with Gluten Free Bisquick.
Gluten Free Veggie Breakfast Casserole
For the filling
- 1 teaspoon olive oil
- one medium sweet onion or half of a large one, finely chopped (set aside 1/4 cup for the crust)
- 1 cup shredded carrots
- 1 medium zucchini, quartered lengthwise, and slide about 1/4 in. thick
- Two 5 oz. packages of baby spinach, chopped into small pieces
- salt and pepper, to taste
- 1 1/2 cups cottage cheese
- 3/4 c shredded sharp cheddar cheese
- 1/2 cup plus 2 Tablespoons grated Parmesan cheese, divided
- 2 egg whites
- 1 egg
- 1 teaspoon dry mustard
For the crust
- 1 cup Gluten Free Bisquick
- 2 egg whites
- 1 egg
- 1/4 cup milk
- 1/4 reserved chopped onion from the filling
- Preheat oven to 350°F. Spray a 9×13 in. square glass baking dish with cooking spray or olive oil.
- Heat oil in a large skillet over medium heat.
- Add the onion, and sauté for 3-4 minutes, or until translucent and starting to soften.
- Add the carrots and zucchini, and sauté for another 5-6 minutes, or until veggies are soft.
- Add the spinach, and cover with a lid for 6-8 minutes, stirring occasionally, or until the spinach is wilted.
- Place the veggies in a bowl and set aside to cool slightly.
- While the vegetables cool, prepare the crust. In a bowl, combine the Bisquick, egg whites, egg, milk, and reserved onion and stir together until smooth. Spread into the prepared baking dish and set aside.
- To the bowl with the vegetables, add the cottage cheese, cheddar cheese, 1/2 cup parmesan cheese, egg whites, egg, and dry mustard, and mix until fully combined.
- Spoon the veggie and cheese mixture on top of the crust, and spread evenly.
- Sprinkle the top with 2 Tablespoons parmesan cheese.
- Bake, uncovered, at 350°F for 30-35 minutes, or until it is cooked through, golden, and bubbly.