Crush or finely chop the garlic. Shred the carrot using a julienne peeler or coarsely grate with a box grater. Thinly slice the spring onion on an angle.
Step 2 — Finish prep
Thinly slice the pak choy, keeping the stems and leaves separate. Trim the lettuce, then separate the leaves.
Step 3 — Make sauce
Put the oyster sauce, 2 tsp white vinegar, 1 tsp soy sauce, 60ml (¼ cup) water and a pinch of chilli flakes* (if preferred, omit the chilli when cooking and serve it at the table) in a bowl and stir to combine.
Step 4 — Cook mince
Heat 1 tbs oil in a large deep frypan over high heat. Cook the pork mince, breaking up the lumps with a spoon, for 3-4 mins until browned.
Step 5 — Cook vegetables
Add the garlic, carrot and pak choy stems to the mince and cook, stirring occasionally, for 2 mins or until the carrot is starting to soften.
Step 6 — Get ready to serve
Add the sauce and pak choy leaves to the mince mixture and bring to the boil. Cook, stirring occasionally, for 2 mins or until slightly reduced. Stir in the cashews. Fill the lettuce cups with the pork mixture. Scatter with the spring onion and sesame seeds to serve.