I like to mix it up and add a little color by using zucchini for half the amount of squash but use what you have or what you like. The sausage makes it different than other squash casseroles. I could eat it as a main dish casserole!
To make this recipe keto diet friendly, omit the milk and add 1/2 cup whipping cream. Omit the breadcrumbs and add 1/2 cup additional Parmesan cheese or a mixture of Colby and Monterey Jack cheese.