It is advisable to prepare the sauce the day before so that it is infused. In a dry frying pan, fry the coriander seeds to make them more fragrant, and grind them in a mortar. Pass the garlic through a press and, together with ground coriander, sugar, salt and pepper, add to the tomato paste and mix. Pour in enough drinking water so that the sauce acquires the consistency of liquid sour cream. If your tomato paste is sweet, you don’t need to add sugar.