I used butternut but my guess is it was meant for crookneck or patty pan... use your judgment and your imagination. I roasted the squash instead of steaming, but either method will work. Actually, the butternut version was a big hit... I didn't inform my guests that it was an accident!
Ingredients
5 - 6 pounds of fresh yellow squash, cooked, drained, and cut into 1-inch pieces (you can cheat here and buy the squash already cubed!)
3 tablespoons olive oil
1 tablespoon kosher salt
½ teaspoon ground black pepper
salt and pepper to taste
1 cup chopped yellow onion
1 cup panko crumbs or bread crumbs (either seasoned or plain, but cut back on salt if using seasoned)
4 eggs, slightly beaten
4 ounces unsalted melted butter (1 stick), plus 2 tablespoons for topping
1 - 2 tablespoons sugar
Instructions
Lightly coat a 9 x 13-inch casserole dish with nonstick cooking spray.
Trim ends of squash and steam until tender. Drain well before chopping.
(If using butternut squash, peel and cut into 1-inch pieces, then put on a baking sheet. Sprinkle with olive oil, salt and pepper and roast in a preheated 300F degree oven for about an hour until tender.)
While squash is cooking, saute onion in butter.
Preheat oven to 375F degrees.
Mix cooked squash, onion, bread crumbs, beaten eggs, melted butter, and sugar together in a large mixing bowl and then put mixture into casserole dish.
Melt a few tablespoons more of butter and add additional crumbs, then spread mixture on top.
Bake for about an hour or until set and browned on top.
Recipe by Food and Friendship at https://www.foodandfriendshipsantabarbara.com/2019/11/07/sunny-side-squash/