Bring a large pot of water to a boil and cook the rice noodles according to package instructions until just tender; drain and set aside.
Whisk the hoisin sauce, fish sauce, soy sauce, and lime juice in a small bowl; set aside.
Prep the garnishes: mince the garlic, chop or julienne the cucumber, chop the mint, prepare the carrot, slice the scallions, and chop the peanuts.
Heat the olive oil in a skillet or wok over medium-high heat. Add the chicken pieces and cook, stirring often, about 5 minutes until browned.
Add the minced garlic to the pan and cook 30 seconds until fragrant, then pour in the prepared sauce and stir to coat the chicken; cook 2–3 minutes more until the chicken is cooked through and the sauce thickens.
Add the drained noodles to the pan and toss with the chicken and sauce until evenly combined; use tongs to mix without breaking the noodles.
Stir in or top with cucumber, mint, carrot, scallions, and chopped peanuts; sprinkle with red pepper flakes to taste and serve with lime wedges.