Fry the finely chopped onion in plenty of olive oil; you should use a large non-stick pan with a high edge, if possible.
While still on low heat, add pepper, tomato paste and 2 cloves of crushed garlic; then, add a large glass of water and 1/2 teaspoon of salt.
When the sauce starts to simmer, put the fish in the pan and cook over medium heat until you obtain a thick sauce. (*) You can also use 300 g of tuna fillets in oil, to speed up the recipe in an unorthodox way, but these must be of excellent quality, very large and compact.
Add a scant 1/2 teaspoon of ground caraway to the sauce, and cook for a few more minutes, then at the end of cooking, add the juice of 1/2 a lemon.
Serve the hraimi as an appetizer, at room temperature, with plenty of bread (the sauce, if it is well made, is usually a huge success!).