In a food processor or a blender, add 3 tablespoons oil, the fish sauce, oyster sauce, red pepper flakes, sugar, shallots, garlic, lemongrass, and lime zest. Process/blend until smooth. Add to a bowl, along with the chicken, and toss to coat the chicken in the marinade. Cover the bowl and refrigerate for 1-4 hours.
Preheat oven to 375 degrees F.
Heat the remaining 2 tbsp oil in a 12-inch ovenproof skillet over medium-high heat. Reserving the marinade, add 4 pieces of chicken to the skillet skin side down. Sear for 4 minutes. Remove from pan and set aside. Repeat with the last 4.
Once all the chicken is seared, arrange them back onto the pan so they are not overlapping (if the pan is not large enough for that you may use a baking dish). Add the reserved marinade back into the skillet and transfer to the oven.
Roast for 30-35 minutes, until the chicken is cooked through. Garnish with chopped basil and serve with lime wedges.
