Yellow Squash Casserole

Bahan-bahan (8 porsi)

• 4 tablespoons unsalted butter (divided)
• 1 medium yellow onion (chopped (about 1 ½ cups))
• 4 medium yellow squash (cut into ¼-inch thick coins (about 3 pounds))
• 1 ½ teaspoons kosher salt (divided)
• 2 large eggs
• 1 (5.3-ounce) container full-fat plain Greek yogurt (about ½ cup)
• ⅔ cup milk
• ½ teaspoon ground black pepper
• ¼ teaspoon dried thyme
• ⅛ to ¼ teaspoon cayenne pepper
• ⅔ cup shredded sharp cheddar cheese
• ⅓ cup shredded Swiss cheese (or additional cheddar cheese)
• 1 sleeve round buttery crackers (such as Ritz, coarsely crushed (about 1 ½ cups))