Fresh tomatoes: cut a small cross on the top of each tomato, place in large bowl and cover with boiling water. Leave for a minute. Drain and rinse with cold water, peel off skins.
Tinned tomatoes: drain off juice and set aside.
Roughly chop the tomatoes; finely chop the onions and garlic. Place the tomatoes, onions, garlic, Chelsea Raw Sugar, vinegar and salt in a large saucepan and bring to the boil. Reduce to a medium heat and gently cook for 15-20 minutes.
Mix the curry powder, mustard powder and cornflour with the extra vinegar to a form a smooth paste. Stir into the tomatoes and cook until thickened.
Spoon into a large, warm, sterilised jar and seal. Refrigerate once opened.
Makes: 1 500ml jar.