Heat 1 tablespoon vegetable oil in a large skillet over medium-high heat. Add the garlic, shallots, and ginger and cook, stirring, for 1–2 minutes or until fragrant but not letting the garlic burn. Add the ground turkey or beef and cook, 5–6 minutes. Add ⅓ cup peanut sauce and the water chestnuts, and continue to cook, stirring, until the ground beef or turkey is sticky and coated, about 3 minutes.

Put the rest of the peanut sauce in a small serving bowl, garnish with a pinch of red pepper flakes and about 1 tablespoon of chopped peanuts.

Serve the ground beef or turkey in lettuce cups topped with relish, peanuts, mint, and cilantro leaves with peanut sauce on the side.