How to Make It
Cut the chicken into 1-inch chunks, then pulse in a food processor until coarsely chopped, about 10 one-second pulses.
In a small saucepan, dissolve the salt and sugar in the water over medium heat. Add the chicken and simmer, stirring frequently, until the chicken is just cooked, about 3 minutes. Turn off the heat and add the shallot, lime juice, cayenne, fish sauce, mint and cilantro. Stir, then spoon into the lettuce cups and serve.