Chop the onions, mince the garlic cloves, remove the seeds from the jalapeno pepper and chop up.

Mix all ingredients except the last 2 tablespoons of oil in a large zip-top bag and let the chicken marinate in the refrigerator for 8 hours or preferably overnight. Remove the chicken from the bag when you are ready to cook, but keep the marinade.

Heat a large saucepan over medium heat and add 2 teaspoons of oil. As soon as it heats up, add the chicken and sauté on both sides for two minutes. Remove and place on a plate.

Scoop the onions from the marinade bag with a perforated spoon, put them in the hot pan, and simmer for 5 minutes. Add the rest of the marinade and allow it to boil. Cook for 10 minutes over medium heat.

Keep cooking the marinade until it turns into a sauce (about 20 minutes). Reduce heat to low, add the chicken to the sauce, cover and simmer until chicken is tender (about 10-15 minutes longer).

Serve with rice