01 -
Preheat oven to 350°F (175°C).
02 -
Melt butter in a large pot over medium heat. Add diced onions and cook for about 5 minutes until softened.
03 -
Stir in the cream of mushroom soup, milk, sour cream, garlic salt, salt, mustard powder, Italian seasoning, and pepper until combined.
04 -
Add 1 cup of shredded cheddar cheese and stir until melted into the mixture.
05 -
Stir in frozen broccoli and mixed vegetables, allowing them to heat through. Remove from heat and let cool slightly.
06 -
Stir in the whisked eggs and cooked rice until well combined. Transfer the mixture to a lightly greased 9 x 13 inch casserole dish and top with remaining cheese.
07 -
Cover the casserole and bake for 20 minutes. Meanwhile, combine crushed Ritz crackers with melted butter.
08 -
Remove the casserole from the oven and sprinkle the cracker mixture on top. Bake uncovered for an additional 10 minutes until golden brown.
09 -
Remove from heat and serve warm.