1/2 cup soy sauce
1/2 cup vinegar or lemon juice
1/4 cup green onions
1/4 cup diced onion
Donne' (use as much or as little as you like)
Optional: You may add cherry tomatos if you like. I would recommend removing some of its juice and seeds. A simple squeeze on the tomato should do the trick.
Mix all ingredients together in a nonmetallic bowl. If you make to much simply put remainder into a container, seal and use later.