Boil Hakka noodles in water with a little salt until they are cooked but firm. Drain and rinse with cold water.
Heat oil in a wok or pan and sauté chopped garlic until fragrant.
Add sliced vegetables and stir-fry on high heat for 2–3 minutes to keep them crunchy.
Add boiled noodles, soy sauce, chili sauce, vinegar, salt, and black pepper.
Toss everything together until the noodles are well coated with the sauces.
Garnish with spring onions and serve hot.