Make the marinade for the chicken by mixing together 2 cloves minced garlic, 1 lime (juiced), 2 tablespoons fish sauce, 1 tablespoon soy sauce, 2 tablespoons brown sugar, and 1 tablespoon vegetable oil.
Add the boneless chicken thighs to the marinade and set aside for 10 minutes to 1 hour.
Prepare the Vermicelli rice noodles according to the package instructions, then drain and rinse with cold water. Set aside.
Make the Nuoc Cham sauce by combining 3 cloves minced garlic, 1 lime (juiced), 2 tablespoons rice vinegar, 1/4 cup fish sauce, 3 tablespoons sugar, 1 red Thai chili (or substitute 2 teaspoons Sriracha), 1/2 cup cold water and stir until the sugar has dissolved.
Heat vegetable oil in a frying pan over medium high heat and sear the chicken for until cooked through. (around 3-5 minutes)
In a large bowl mix the rice noodles with bean sprouts, julienned carrots and cucumber, romaine lettuce, mint, and cilantro. Then slice the chicken thighs and add to the salad. Serve with Nuoc Cham sauce and enjoy!