Add potatoes and cauliflower to a pot, cover with water and boil for 20 minutes until fork tender then drain and mash well then add 1 tablespoon butter, milk, 1 teaspoon salt and 1/2 teaspoon pepper and reserve to the side.
To a large cast iron skillet add remaining butter and onion, sautéing until softened, for about 5 minutes.
Add in the turkey, garlic, carrot, corn, peas, flour, and the remaining salt and pepper stirring well for an additional 2-3 minutes.
Add the turkey mixture to the baking dish, top with the mashed potatoes and cheddar cheese and bake for 30-35 minutes.
Note: click on times in the instructions to start a kitchen timer while cooking.