Healthy Cheesy Summer Squash Casserole

gold spoon lifting cheesy summer squash casserole out of a blue baking dish.

5 from 1 reviews

This delicious cheesy, healthy summer squash casserole recipe is so simple to make and is the perfect summer side dish for using all of those yellow squash or zucchini! (vegetarian, nut-free)


  • 4 medium yellow squash (about 3 cups after grating and squeezing the water out)
  • 4 cloves garlic, minced
  • 1/2 small onion, minced
  • 1 tbsp wheat flour
  • 1 1/2 cups milk
  • 1 large egg
  • 1/2 tsp sea salt
  • 1/2 tsp black pepper
  • 1/2 cup freshly grated parmesan or gruyere + 1/4 cup parmesan for topping
  • 1/4 cup whole wheat bread panko or bread crumbs (regular works too)


  1. Heat oven to 400° F.
  2. Line a colander or bowl with paper towels or a clean dish towel. Grate squash onto paper towels and squeeze out as much liquid as you can.
  3. Chop onions and garlic. Grate the cheese.
  4. Whisk together flour, milk, egg and pepper in a large bowl. Add squash, onions, garlic and all of the cheese except for 1/4 cup of the parmesan and stir gently to combine.
  5. Pour mixture into a lightly greased 8-inch baking dish.
  6. Sprinkle panko and parmesan over the top of the squash and bake for 30 minutes, or until squash is bubbly and top is golden.
  7. Place under the broiler for 1-2 minutes to crisp the top (optional). Remove from oven and serve hot.


This recipe can be doubled for a 9x13 inch dish.

To make ahead, simply make the filling and spread into the baking dish. Cover and refrigerate until ready to bake, up to 1 day. When you're ready, sprinkle with panko and parmesan and bake.

For gluten-free, use your favorite gluten-free bread crumbs and 1-to-1 gluten-free all purpose flour.

Keywords: healthy cheesy squash casserole, healthy summer squash casserole