This mixed vegetable casserole features a creamy, cheesy base of frozen veggies and a crisp cracker topping. It's a simple bake that’s anything but boring.
This mixed vegetable casserole doesn’t try to be fancy, but it nails the fundamentals: salty crunch, creamy middle and vegetables that taste better than they have any right to. The filling is rich and savory, held together by sharp cheddar and mayonnaise. On top, crushed crackers soak up melted butter and bake into a golden, craggy crust that crumbles under your fork.
What makes this casserole worth it is how little effort it takes to produce that kind of payoff. You stir everything in one bowl, scoop it into a baking dish and let the oven take care of the rest. No precooking, no sauces to fuss over and no last-minute garnishes. It’s the kind of dinner that doesn’t ask much of you, but still delivers warmth, comfort and just enough crunch to keep things interesting.
Mixed Vegetable Casserole Ingredients
- Frozen mixed vegetables
- Onion
- Celery ribs
- Shredded cheddar cheese
- Mayonnaise
- Crushed butter-flavored crackers
- Butter
Directions
Step 1: Combine the main ingredients

Preheat the oven to 350°F. Add the vegetables, onion, celery, cheddar and mayonnaise to a large bowl.

Mix to combine the ingredients and coat them in the mayonnaise.

Spoon the mixture into a greased 1-1/2-quart baking dish.
Step 2: Add the topping and bake

Combine the cracker crumbs and melted butter until they’re crumbly.

Sprinkle the mixture over the top.

Bake the casserole, uncovered, for 30 to 35 minutes or until it’s heated through.

How to Store Mixed Vegetable Casserole
Let the casserole cool completely, then transfer any leftovers to a food storage container and refrigerate. Stored this way, the casserole will stay fresh for three to four days. For the best texture, reheat leftovers in the oven rather than the microwave to crisp the topping.
Mixed Vegetable Casserole Tips

Can you use fresh vegetables instead of frozen in this mixed vegetable casserole?
You can use fresh vegetables in this casserole, but you should lightly steam or saute them before mixing them with the other ingredients. This helps match the texture and moisture level of thawed frozen vegetables.
What kind of crackers work best in mixed vegetable casserole if you don’t have butter-flavored crackers?
If you don’t have butter-flavored crackers, you can swap in saltines or oyster crackers for the topping on this casserole. If you’re feeling ambitious, try making the topping with homemade crackers!
Can you make mixed vegetable casserole ahead of time?
You can assemble this mixed vegetable casserole up to one day ahead and refrigerate it, covered. For the best texture, wait to add the cracker topping until the last minute, just before the casserole goes in the oven.
What goes well with mixed vegetable casserole for a full meal?
Mixed vegetable casserole pairs well with roast chicken, baked ham or grilled pork chops. For a lighter option, serve it as a main with a crisp green salad or a bowl of tomato soup on the side.
Ingredients
- 1 package (16 ounces) frozen mixed vegetables, thawed
- 1 large onion, chopped
- 3 celery ribs, chopped
- 1 cup shredded cheddar cheese
- 1 cup mayonnaise
- 3/4 cup crushed butter-flavored crackers
- 1/4 cup butter, melted
Directions
- In a large bowl, combine the first five ingredients. Spoon into a greased 1-1/2-qt. baking dish. Combine the cracker crumbs and butter until crumbly; sprinkle over the top. Bake, uncovered, at 350° for 30-35 minutes or until heated through.