Red Pepper Sauce for Nut Roast

Name: Red Pepper Sauce for Nut Roast
Prep time: 10 min
Cook time: 15 min
Total time: 25 min
Cuisine: British
Ingredients: 1 tablespoon olive oil; 1 onion (white, brown or red), finely chopped; 2 cloves garlic , crushed or finely grated; 1 red bell pepper, topped, deseeded and finely chopped; 400g (14 oz canned) chopped tomatoes; 2 tablespoons tomato puree; 1 tablespoon balsamic vinegar; ½ teaspoon chilli flakes (more if you like); ½ teaspoon paprika; 1 teaspoon dried basil (or a small handful of fresh - see notes); 1 pinch of salt and pepper