1 large red onion, peeled and chopped
1/2 bulb fennel, trimmed and chopped
1 stick celery, trimmed and chopped
Olive oil
2 tbsp. chopped ginger
1/2 a fresh red chili, deseeded and finely chopped
Bunch fresh basil, leaves picked, stalks chopped
1 tablespoon coriander seeds
2 cloves
Salt or Sea salt
1 teaspoon black pepper
2 pounds cherry or plum tomatoes, cut in half
3/4 cup red wine vinegar
1/3 cup soft brown sugar
Place all the vegetables in a large heavy-bottomed saucepan with a dash of olive oil, ginger, garlic, chili, basil stalks, coriander seeds and cloves. Season with the pepper and a little salt.
Cook over a low heat for 10 to 15 minutes until softened, stirring every so often. Add all the tomatoes and 1 1/2 cups of cold water. Bring to boil and simmer gently until the sauce reduces by half.
Add the basil leaves, then put the sauce in a food processor or with a hand blender and push it through a sieve twice. Put the sauce into a clean pan and add the vinegar and the sugar. Place the sauce on the heat and simmer until it reduces and thickens to the consistency of tomato ketchup. You can add seasoning to taste.