Preheat oven to 400 degrees F. Combine the garlic salt, salt, pepper, and Old Bay seasoning. Sprinkle the seasonings evenly over both sides of the steaks. Let stand for 20 minutes. Dust the steaks with the flour. Melt the butter in a large skillet over medium-high heat. Add the steaks and brown lightly on both sides, 2 to 3 minutes per side. Place into a 1 1/2-quart casserole dish. Sprinkle the onion slices over the meat. Add any remaining flour to the skillet that the meat was cooked in. Stir until the flour is absorbed. Add the water and cook over high heat, stirring up the browned bits from the bottom of the pan. Bring to a boil, then reduce the heat and simmer for 1 minute. Pour over the steaks. Cover and bake for 35 minutes or until the meat is tender.