Southern Onion Casserole

Closeup of the finished onion casserole in a white casserole dish.

Creamy, cheesy Southern onion casserole is topped with buttery cracker crumbs. It's a perfect comfort food side dish for fall & winter and can be assembled ahead and baked when you're ready.

Course Side Dish

Cuisine American - Southern

Prep Time 10

Cook Time 50

Total Time 1

Servings

Calories 440kcal

Author Marye Audet-White

Ingredients

4 large onions sliced to ¼-inch thickness, about 1 ½ pounds of onions
2 tablespoons butter
3 eggs
⅔ cup evaporated milk 5 ounces
1 cup Ritz cracker crumbs
1 ½ cups grated cheddar cheese grate from a block
½ cup Mozzarella grated from a block.
1 teaspoon salt
¼ teaspoon black pepper

Topping:

1 cup Ritz cracker crumbs coarsely crushed
3 tablespoons butter melted

Instructions

Grease a 13x9 inch pan.
Preheat the oven to 375F.
Place onions in a saucepan and cover with water.
Bring to a boil and simmer until tender - about 6-8 minutes.
Drain and put back in the pan.
Stir in butter.
In a large mixing bowl whisk the eggs and evaporated milk together until combined. Add the onion and butter mixture.
Stir in the Ritz cracker crumbs, grated cheddar cheese, grated Mozzarella, salt, and pepper.
Add to prepared 13x9-inch pan.
Combine topping ingredients in a small mixing bowl and sprinkle on top of the mixture in the prepared pan.
Bake for 40-45 minutes, or until heated through. It will register 165F on an instant read thermometer.

Notes

Storage:

Cover the baking dish with foil (or transfer leftovers to an airtight container) and refrigerate for up to four days.

You can also freeze onion casserole for up to three months.

The best way to reheat Southern onion casserole is in the oven—it'll crisp up the topping again.

Tips:

Sweet onions sometimes go by other names, like Vidalia, Maui, or Walla Walla.
Cut ¼ inch thick for best results.

Don't let the onions get too soft while simmering. Just cook them until you can easily pierce them with a fork, about 6-8 minutes.

Freshly shredded cheese tastes better and melts much smoother than pre-shredded cheese from a bag.

Nutrition