This gluten free casserole recipe combines tender chicken, fluffy rice, fresh broccoli, a homemade gluten-free cheese sauce, and plenty of melted cheese in one comforting baked dish. It's family-friendly, freezer-friendly, perfect for meal prep, and delivers classic casserole flavor without gluten-containing ingredients.
Preheat the oven to 375°F and grease a 9x13-inch casserole dish with butter or cooking spray.
Melt 2 tablespoons butter in a skillet. Add the onion and garlic and cook for 3 to 4 minutes until softened and fragrant. Set aside.
In a saucepan, melt 3 tablespoons butter. Whisk in the gluten-free flour and cook for 1 minute. Slowly add milk while whisking. Simmer until slightly thickened, then stir in 1 cup cheddar cheese, salt, and pepper until smooth and creamy.
In a large mixing bowl, combine the chicken, rice, broccoli, onion mixture, cheese sauce, 1 cup cheddar cheese, mozzarella cheese, paprika, onion powder, garlic powder, salt, and black pepper. Mix until evenly coated.
Transfer the mixture to the prepared baking dish and spread evenly.
Top with the remaining cheddar cheese.
Bake for 25 to 30 minutes until light golden brown, bubbling in the center, and slightly crisp around the edges.
Allow the casserole to rest for 5 minutes before serving.
Notes
Use certified gluten-free flour and verify all packaged ingredients are gluten-free. Do not overcook the broccoli before baking since it will continue cooking in the oven. Allow the casserole to rest for 5 minutes before serving. Store leftovers in an airtight container for up to 4 days or freeze for up to 3 months.