Onion Marmalade - cooking recipe

Ingredients

2 2/3 lb large red onions, sliced
1/2 cup malt vinegar
2/3 cup firmly packed brown sugar
2 tsp orange zest
1/2 cup orange juice

Preparation

Bring onions and 1 2/3 cups water to a boil. Boil, stirring occasionally, for 20 mins, or until onions are soft and liquid has evaporated.
Add remaining ingredients and stir, without boiling, until sugar has dissolved. Simmer, covered, for 30 mins. Remove cover and simmer, stirring occasionally, for another 30 mins, or until mixture thickens.