Prepare the paste: Blend garlic, banana shallots, red chili, and water until smooth. Set aside.
Prepare the sauce: Mix all sauce ingredients in a small bowl and set aside.
Cook chicken and paste: Heat oil in a wok over medium heat. Add the paste and stir-fry for 1 minute until fragrant. Add chicken and stir-fry for 1 minute.
Add noodles and veggies: Add choi sum, cooked noodles, fried tofu, and the pre-mixed sauce. Stir-fry for 2 minutes until everything is well-coated and heated through.
Add final vegetables: Stir in bean sprouts and spring onion. Cook for 1 more minute, then squeeze lime over the top.
Serve and garnish: Transfer to a plate and garnish with extra chopped spring onion and fried shallots.