Wash the squids very well. Remove the long thin membrane in the head and slit the eyes to bring out the ink. Place the squids in a saucepan with vinegar, 6 cloves garlic crushed, salt and pepper. Cover and cook slowly until the squids are tender.
Cut cooked squids into 1 cm slices crosswise.
Crush remaining garlic and saute in a little lard in another pan. Add the onion and tomatoes and cook until tomatoes are very soft. Add the squids and the liquid in which they were boiled. Simmer for 7 minutes.
Season with salt, pepper and vet-sin.