Mixed vegetable casserole is a creamy baked side dish of broccoli, carrots, peas, and other vegetables in a cheddar and mayonnaise sauce, topped with buttery cracker crumbs for a golden crunch.
It takes fifteen minutes to prepare and about forty to bake, so it is a dependable side for a weeknight dinner, a potluck, or a big family dinner with roast meats.
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Why This Mixed Vegetable Casserole Recipe Works
A sauce of mayonnaise and cheddar stays smooth in the oven and coats every vegetable, with no roux to stir on the stove.
Onion and celery add savory depth, so the casserole tastes like more than just cheese and vegetables.
A topping of buttery cracker crumbs bakes into a crisp, golden crust that contrasts with the soft vegetables underneath.
Ingredients for Mixed Vegetable Casserole
- You need a bag of frozen mixed vegetables, onion, celery, shredded cheddar, mayonnaise, a splash of milk, garlic powder, pepper, buttery round crackers, and melted butter for the topping.
- Thaw the frozen vegetables and drain them very well, because extra water makes the casserole soupy.
Mixed vegetables. They provide color, sweetness, and a tender bite.
Onion and celery. They add savory flavor and a little crunch.
Mayonnaise and cheddar. They make a creamy, tangy sauce that stays smooth.
Cracker crumbs. They bake into a crisp, buttery topping.
Garlic powder. It adds a gentle savory background note.
How to Make Mixed Vegetable Casserole
1. Heat the oven. Heat the oven to 375 degrees F and grease a two quart baking dish.
2. Prepare the vegetables. Thaw and drain the vegetables, then pat them dry and mix them with the chopped onion and celery.
3. Make the sauce. Stir the mayonnaise, most of the cheddar, a splash of milk, garlic powder, and pepper until smooth.
4. Combine. Fold the sauce into the vegetables and spread the mixture in the baking dish.
5. Add the topping. Mix the crushed crackers with the melted butter, sprinkle them over the casserole, and top with the remaining cheddar.
6. Bake. Bake for thirty to forty minutes until the top is golden and the edges bubble, broiling for the last few minutes if you want a crunchier crust, then rest for five minutes.
Chop the onion and celery fairly small, because large pieces stay crunchy and stand out against the soft vegetables.
If the sauce looks stiff, add another splash of milk, since the vegetables absorb some of it as the casserole bakes.
Let the dish rest for five minutes before serving so the sauce settles and the casserole slices cleanly.
How to Serve Mixed Vegetable Casserole
Serve the casserole as a side with roasted chicken, baked ham, or grilled meats. It pairs well with hobo casserole with ground beef on a casserole night, or with slow cooker rump roast vegetables for a family dinner. You can also bring it to a potluck beside leftover chicken rice casserole and Italian sausage and pepper casserole.
How to Store and Reheat Mixed Vegetable Casserole
Cover leftovers and refrigerate for up to four days. Reheat in the oven at three hundred fifty degrees F for fifteen to twenty minutes, or in the microwave in single portions. Freeze the cooled casserole for up to three months, though the topping will be softer after reheating.
Tips and Variations for Mixed Vegetable Casserole
Flag the allergens. This casserole contains egg, milk, wheat, and soy from the mayonnaise, cheese, and crackers, so warn guests with allergies and check each label.
Drain the vegetables. Excess water thins the sauce and makes the topping soggy.
Use sharp cheddar. It gives more flavor than mild cheese.
Crush the crackers. Leave some larger pieces for crunch.
Lighten it up. Replace half the mayonnaise with plain Greek yogurt, and adjust the salt to taste since the cheese is already salty.
Add protein. Stir in diced ham or cooked chicken for a main dish.
Use a shallow dish. More surface area gives more crunchy topping.
Check trusted guidance. For safe storage of leftover casseroles, read the Purdue Extension guide to storing leftovers.
The casserole is very flexible, so you can use fresh vegetables like broccoli, carrots, and peas, cut into small pieces and steamed briefly first.
A pinch of onion powder in the sauce adds more savory flavor without extra chopping.
Frequently Asked Questions About Mixed Vegetable Casserole
What is mixed vegetable casserole?
It is a baked side dish of mixed vegetables in a creamy cheese sauce with a crisp cracker topping.
Can I make mixed vegetable casserole ahead of time?
Yes, assemble it a day ahead, add the topping just before baking, and bake it as directed.
Can I use fresh vegetables in mixed vegetable casserole?
Yes, blanch them for a few minutes first, then use them in place of frozen.
Can I use something other than mayonnaise?
Yes, sour cream or Greek yogurt can replace some or all of it.
Can I skip the cracker topping?
Yes, use breadcrumbs or crushed cornflakes instead.
Mixed Vegetable Casserole
Equipment
- Two quart baking dish
- Mixing bowl
- Colander
Ingredients
- 16 oz frozen mixed vegetables thawed and drained
- 1 onion chopped
- 2 celery stalks chopped
- 1 cup shredded cheddar cheese
- ¾ cup mayonnaise
- 2 tbsp milk
- ½ tsp garlic powder
- ¼ tsp black pepper
- 1 cup crushed buttery round crackers
- 2 tbsp butter melted
Instructions
- Heat. Heat the oven to 375 degrees F.
- Mix. Mix the vegetables, onion, and celery.
- Sauce. Stir the mayonnaise, cheese, milk, garlic powder, and pepper.
- Combine. Fold the sauce into the vegetables and spread in a dish.
- Top. Top with crackers mixed with butter.
- Bake. Bake thirty to forty minutes until golden.
