Mix 2 tbsp oyster sauce, 2 tsp Shaoxing wine, 2 tbsp soy sauce, 2 tsp brown sugar, and 2 tsp sesame oil.
Heat a pan until very hot, reduce to medium-high, and add a splash of sesame oil.
Cook minced garlic, diced onion, bell pepper matchsticks, carrot matchsticks, sugar snaps, water chestnuts or bamboo shoots, and sliced pak choi stems for 1 minute.
Add the pak choi leaves, then pour in the sauce.
Toss through udon noodles using tongs
Serve with prawn crackers.