Warm up with this hearty Onion Soup Sauce recipe. Made with onions, butter, sherry and sherry vinegar. Easy step-by-step instructions included.
This Onion Soup Sauce relies on simple, everyday ingredients such as (200 g) thinly sliced onions, (55 g) unsalted butter, dry sherry (optional) and leaves from 4 sprigs thyme. It comes together quickly and makes 4 servings, at about 160 kcal each. The step-by-step instructions below are written to be easy to follow, even on a busy day.
It works as a light main on its own or as a starter alongside crusty bread, and it's just as good for a cozy night in as it is for feeding a crowd. Leftovers keep well, so it's a smart choice for meal prep too.
Updated Jun 30, 2026