Lightly pound steaks with a meat mallet until they are about ¼ inch thick. Mix buttermilk, Tabasco, 1 teaspoon salt and ¼ teaspoon pepper in a shallow dish.
Combine flour with remaining 1 teaspoon salt and ¼ teaspoon pepper in another shallow bowl. Mix well. Dredge flattened sirloin in flour to coat evenly. Submerge steaks, one at a time, in buttermilk mixture. Return steaks to flour and dredge again. Press flour firmly into surfaces of steaks so it will adhere.
Pour peanut oil into a deep, broad skillet to a depth of ½ inch. Carefully place one coated steak into hot oil. Fry about 3 minutes, turn carefully, and fry other side 3 minutes, or until crust is golden brown and steak is to desired doneness. Transfer steak to a plate lined with paper towels. Keep warm. Repeat procedure for other steaks.
Peppered Cream Gravy: Melt butter in a saucepan over medium-high heat. Whisk in flour and sauté until lightly browned. Remove pan from heat. Pour in milk in a steady stream, whisking vigorously. Return pan to heat and whisk until sauce thickens. Whisk in cream, salt, and pepper. Place steaks on plates and top with gravy. Serves 4.