Currywurst Sauce - cooking recipe

Ingredients

2 large red onions or 2 large yellow onions, chopped very finely
2 (15 ounce) cans tomatoes with juice
1 cup ketchup
1 tablespoon mustard
2 tablespoons sugar
4 tablespoons Worcestershire sauce
1 tablespoon paprika
2 tablespoons curry powder
1/2 teaspoon chili powder
to taste salt and pepper
1 tablespoon oil

Preparation

Warm oil over medium heat.
Put onions in pan and cook over medium heat until soft, 8 to 10 minutes.
Add curry powder, paprika powder, chilli powder and continue to cook while stirring, for one to two minutes.
Add tomatoes and juice to pan and crush thoroughly, stir through.
Stirring add ketchup, Worcestershire sauce, sugar, mustard, salt and pepper to taste.
Bring to boil and lower to simmer, stirring occasionally until thickened. 20-25 minutes.
Puree mixture in blender and strain through a sieve.