Score the tomato skin and place the tomatoes in hot water for about 1 minute. Then skin and cut into large cubes. Core the pointed peppers, first cut into strips, then into small cubes. Core the pepper, cut into strips, then into small cubes. Put everything in a bowl with the lemon juice and stir. Pour into a chopper and chop to the desired consistency.
Put the mixture with the preserving sugar in a saucepan, stir and bring to the boil. Reduce the heat and simmer for about 10 minutes, stirring frequently.
If the jam is still too chunky for your own taste, crush everything in the pot with a normal potato masher and stir.
Remove from the stove, put 1 teaspoon of the mixture on a small plate and check whether the jam is no longer too runny. If so, add a little citric acid and stir in.
Now pour the hot mixture into small glasses (twist off), close immediately and allow to cool.