Zucchini Casserole

A fresh zucchini casserole with sautéed onions and garlic in a creamy cheese sauce topped with buttery Parmesan Panko breadcrumbs.

Course Side Dish

Cuisine American

Keyword cheesy zucchini casserole, how to make zucchini casserole, zucchini casserole recipe

Prep Time 20

Cook Time 30

Servings servings

Calories 376kcal

Author Beth Pierce

Preheat oven to 375 degrees. Spray a 2 1/2 quart casserole with nonstick cooking spray.
Heat 1 tablespoon olive oil in a large pan over medium-high heat. Add the onion and cook until soft. Reduce the heat to low and add the garlic, cooking for 1 minute while stirring constantly. Plate the vegetables.
Heat the other tablespoon of olive oil in the skillet over high heat until it sizzles when the zucchini touches it. Add the zucchini and cook just until very lightly browned, stirring a couple of times. Plate the zucchini.
Reduce the heat to medium. Using the same skillet, melt the butter. Once melted, whisk in the flour. Cook for 2 minutes while whisking constantly. Slowly add the milk while whisking. Whisk in the salt, black pepper, and nutmeg and cook until thickened. Reduce the heat to low and whisk in the cheddar cheese 1/2 cup at a time until melted.
Meanwhile, in a small bowl, combine the butter, Panko breadcrumbs, and Parmesan Cheese. Add the zucchini mixture to the prepared casserole dish. Pour the cheese sauce over the zucchini mixture and stir to coat. Sprinkle with the panko breadcrumb mixture. Bake for 25-30 minutes or until lightly browned and bubbly.

The zucchini is cooked on high in the skillet long enough to cook most of the moisture off and prevent a watery casserole. You don't want to cook it tender because you will bake it.
This recipe works well with yellow squash too.
For best results, use medium zucchini. The larger zucchinis can be tough, so it is best to avoid them.
You can slice it into rounds, but I quarter it first and then slice zucchini at about 1/3-1/2 an inch.
Nutmeg adds just a touch of sweetness, but if you don't like nutmeg, try something more savory, like marjoram or thyme.
If a little added flavor or kick is desired, add a little crushed red pepper, cayenne pepper, or creole seasoning.
Garnish the casserole with chopped fresh parsley or thyme.
This casserole is best enjoyed fresh out of the oven while warm and melty.
Store leftovers in an airtight container in the refrigerator for up to 3 days.
I do not recommend freezing this casserole. The amount of water in the zucchini combined with the béchamel cheese sauce will separate.