How To Make Squash Casserole - Best Recipe | Charleston Magazine

Ingredients

• 11 lbs. mixed zucchini and yellow squash, sliced into 1/8-inch rounds
• Kosher salt
• 3 lbs. white onion, peeled and thinly sliced
• 2 garlic cloves, minced
• 2 tsp. sugar
• 6 short thyme stems
• 2 fresh bay leaves
• 1/4-inch strip of lemon peel with the pith removed
• 3 cups water
• 3 eggs
• 5 egg yolks
• 1/2 cup mayonnaise, Duke’s preferred
• 11/2 cups grated Gruyère cheese, divided
• Fresh ground pepper
• 1 Tbs. lemon zest
• 1/4 cup chopped flat-leaf parsley, divided
• 23/4 cups dried bread crumbs or panko, divided
• 1 Tbs. unsalted butter at room temperature
• 1/4 cup unsalted butter, melted