Preheat oven to 400.
Toss the olive oil, cut squashes, first teaspoon of salt, and Creole seasoning in a large mixing bowl. Spread the squash onto a large baking pan and roast in the oven for 15 minutes.
While the squash is roasting, melt the butter over a medium heat in a small sauté pan.
Remove the squash from the oven and place it into a colander. Gently press the squash to remove as much excess moisture as possible. Add the yellow onion, red bell pepper and celery and cook for 2-3 minutes. Add in the garlic, salt, pepper and green onions and cook for 3 more minutes.
Place the cooked squash, the onion mixture, fresh basil, sour cream, and cheddar cheese and in a large mixing bowl. Use a rubber spatula or wooden spoon to gently fold the mixture together until the sour cream has been incorporate well.
Lower the oven to 325.
Place squash mixture into a 2 quart baking dish. Combine the bread crumbs, parmesan cheese, parsley and melted butter and top the casserole evenly.Bake for 20 minutes.
Yield: 8-10 servings