Heat the peanut oil in a saucepan. Chop the onion and fry briefly. Add minced or crushed garlic cloves. Stir in the tomato puree and tomato paste. If that`s too thick for you, you can add half a glass of water. Crush the mustard seeds and puree them with the vinegar in the sauce. Then drizzle in the stevia syrup, add a pinch of cumin and season the sauce with salt, pepper and chilli to taste. When it starts to boil, take it off the stove and let it cool down briefly. Finally stir in the smoke aroma and let cool down completely.