Heat the butter in a pan over medium-low heat. Add the onions and bay leaf and season the onions with thyme, salt and pepper. Cook to caramel in color and very soft, 40-45 minutes, stirring occasionally. Sprinkle the caramelized onions with flour, cook for 1 minute, then stir in the sherry and deglaze the pan. Add the beef consommé and simmer gently for 5 minutes, until a very thick sauce forms.
Meanwhile, heat a cast iron skillet or griddle over medium-high heat. Pat the steaks very dry and drizzle the pan with oil. Rub a paper towel over bottom of the pan to make sure the oil coats the whole surface and to remove any excess. Add the steaks and cook 4 minutes on each side for a pink center. Season the steaks with salt and pepper.
Place two toast points on each dinner plate. Top the steaks with the onion sauce and serve with sliced ripe tomatoes and creamed spinach. Garnish with Sour Cream and Onion Rings, if you’re an all-out onion lover.