Simmer the water, soy sauce and sugar in a sauce pan over medium heat until it turns a deep caramel color, about 10-15 minutes.
Mix the fish sauce, lime juice, chili sauce, serrano chili and garlic and carefully add it to the pan without splashing the caramel then heat until the caramel dissolves.
Marinate the chicken wings in ½ of the sauce for 60 minutes to overnight.
Place the chicken wings on a rack, on a foil lined baking and bake in a preheated 400F oven until golden brown and crispy, about 20-30 minutes.
Meanwhile place the other half of the in a sauce pan and simmer over medium heat to thicken, about 7-10 minutes.
Toss the wings in the caramel sauce, top with chopped cilantro and serve.
