In a large bowl, stir turkey, egg, breadcrumbs, half the diced onion, ketchup and spices together until combined. Form 6-7 patties and brown both sides in 1 tablespoons olive oil in large, deep skillet. Remove from pan and set aside. Patties will not be cooked completely and that's totally ok!
Pour in remaining 1 tablespoon of olive oil into skillet. Saute last of the onions and mushrooms until browned and tender, about 5 minutes. Remove from pan and set aside.
Melt tablespoon of butter into pan. Sprinkle in flour and whisk to form a paste. It might seem to form crumbs because it's a little dry; that's ok! Slowly whisk in beef broth to avoid lumps. Bring to boil to thicken, then reduce heat to simmer. Pour in Worcestershire sauce. Slide in browned turkey steaks and spoon sauce over to coat. Add in cooked mushrooms and onions overtop and cover. Simmer 10 minutes or until gravy thickens even more and turkey steaks and cooked thoroughly.
Serve over mashed potatoes {or in my case, riced cauliflower}.