- Cut the prawns in to small chunks and add them to a mixing bowl along with the marinade ingredients.
- Add the shiitake mushrooms, carrots and water chestnuts in to the mixing bowl and let marinate for about 15 minutes.
- To make the lettuce cups, remove the outer layer of the lettuce and cut out the stem of the lettuce.
- Remove the leaves of the lettuce and trim them in to cup shapes with enough space to put the fillings in to them.
- Store the trimmed leaves in a large bowl of cold water and keep cool until they are served.
- In a large pan or wok, add 1 tbsp of oil and saute the garlic and green onions until fragrant.
- Add the marinated prawn mixture in to the pan and stir-fry until the prawn has cooked through.
- Add in the Shaoxing wine and cook until almost all of the liquid has evaporated.
- Add in the oyster and soy sauce and stir until well combined before adding the cornflour mixed with 2 tbsp of cold water.
- Stir the cornflour mixture until the sauce begins to boil and thicken before removing from the pan.
- To serve, place a couple of the lettuce leaves on to a plate and fill with the prawn filling.