Preheat oven to 450°. Heat butter in a large skillet until melted. Add onions and cook until tender; do not brown. Remove from heat.
Combine eggs and sour cream in a bowl and mix well. Stir into onions. Add pepper, salt, and TABASCO® Sauce; mix well and spoon into pie shell.
Bake for 20 minutes. Sprinkle cheese over top. Reduce heat to 325°F and bake 20 minutes longer.
Makes 6 servings.
Adapted from "Entirely Entertaining: In The Bonnet House Style."