3 tablespoons butter
4 large onions, sliced
2/3 cup firmly packed brown sugar
1/2 cup brown malt vinegar
1 teaspoon finely chopped fresh rosemary
Heat butter in large pan, add onions, cook gently for 20 to 30 minutes until onions are very soft and lightly browned. Add sugar, stir to melt sugar, simmer uncovered, stirring occasionally until mixture is thick and caramelized. Add vinegar and simmer uncovered for about 5 minutes until thickened slightly. Stir in the rosemary.