Tuna steaks (about 600 grams) - 2 large onions - olive oil - balsamic vinegar - salt and pepper.

Convert european unity of measure

1. Cut the onion into thin slices; to sweeten the onion, soak in water (to which a desert spoon of white vinegar has been added) for about 15 minutes.
2. Heat the olive oil in a frying pan, add the onion and cook till transparent Spinkle pepper and salt over the tuna steaks and place in the frying pan.
3. Dry with paper towels
4. Place tuna steaks in the frying pan after the onion has started to turn transparent.

   

   

5. After cooking for a few minutes turn them over and add a sprinkling of balsamic vinegar (one desert spoon for every two tuna steaks).