Cut the meat into strips.
In a small bowl, mix the Worcestershire sauce, soy sauce, vinegar, ketchup and 1 tsp of sugar. Add the sliced ??meat and marinate for 15 minutes.
Heat some oil in a wok. Remove the meat from the marinade, mix with 1 tsp cornflour. Reserve the marinade. Stir-fry the meat strips in the wok in batches until browned. Then remove them from the wok.
Peel and finely slice the carrots.
Peel and finely dice the onion.
Stir-fry the onion and carrot in 2 tbsp oil in the wok.
Pour in the marinade, add the stock and bring to the boil.
Wash, deseed and finely slice the chillies.
Peel the ginger and garlic. Finely slice the garlic.
Grate the ginger into the wok and add the garlic and chillies.
Peel the pineapple, cut into wedges, remove the stalk and cut the wedges into thin slices.
Wash and halve the tomatoes.
Stir the remaining cornflour with 150ml cold water until smooth, add to the sauce and bring to the boil again. Add the meat, tomatoes and pineapple and leave to simmer for a few minutes.
Wash the cucumber, halve lengthways, scrape out the seeds and cut into thin slices.
Add to the wok, mix and season with sugar and lemon juice. Serve garnished with basil.