In a large gallon ziplock bags mix together soy sauce, vegetable oil, lime juice or citric acid, water, brown sugar, garlic and whole bunch of cilantro.
Place chicken breast in bag and marinate in fridge between 30 minutes up to 2 hours. Do not marinate longer than 2 hours.
Preheat grill on high heat for 5 minutes and reduce to medium heat.
Place each marinated chicken breast top side down on grates and close lid.
Cook for 6 minutes then flip and cook for an additional 6 minutes.
Chicken is cooked through when the internal temperature is 165 degrees.
While chicken is cooking, melt butter.
Stir in lime zest and chopped cilantro.
Generously brush each chicken breast with cilantro lime butter.
Squeeze lime juice over chicken to taste.
Let chicken rest for 5-10 minutes before slicing and serving.