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Summer Squash Casserole

Prep time 20 mins
Cook time 21 mins
Stand time 10 mins
Yield Makes 8 servings


  • 6 tablespoons butter, divided
  • 1 cup chopped onion
  • 2 1/2 pounds yellow squash, sliced
  • 1 cup mayonnaise
  • 2 large eggs, lightly beaten
  • 1 tablespoon all-purpose flour
  • 2 teaspoons sugar
  • 1/2 teaspoon salt
  • 1 (10-oz.) block sharp Cheddar cheese, shredded
  • 1/3 cup soft, fresh breadcrumbs

How to Make It

  1. Microwave 4 Tbsp. butter in a large microwave-safe bowl at HIGH 1 minute or until melted. Add onion, and cover bowl tightly with plastic wrap, folding back a small edge to allow steam to escape. Microwave at HIGH 2 minutes.

  2. Uncover, add squash, and cover bowl tightly with plastic wrap, folding back a small edge. Microwave at HIGH 5 minutes or until squash is tender. (Do not drain.)

  3. Combine mayonnaise and next 4 ingredients in a large bowl. Stir in squash mixture and cheese.

  4. Spoon mixture into a lightly greased 11- x 7-inch baking dish. Cover dish tightly with plastic wrap, folding back a small edge.

  5. Microwave at HIGH 10 minutes or until casserole is set. Remove and let stand 10 minutes.

  6. Microwave remaining 2 Tbsp. butter at HIGH 1 minute or until melted. Stir together melted butter and breadcrumbs; microwave at HIGH 2 minutes. Sprinkle over casserole.

  7. Note: The onion and squash release excess moisture when cooking; do not drain. The flour in the mayonnaise mixture will help absorb the moisture.