Mix together all the ingredients for the marinade, then rub them all over the chicken thighs, cover and set aside in the fridge to marinate for 30 minutes.
Heat enough oil for deep-frying in a deep-fat fryer or a deep, heavy-based saucepan to 190C/375F (CAUTION: Hot oil can be dangerous. Do not leave unattended). Add the chicken pieces and deep-fry for about five minutes, or until they are crisp, golden-brown and just cooked through. Drain on a plate lined with kitchen paper and set aside.
For the stir-fry, heat the oil in a heavy pan until it reaches smoking point. Add the dried red chillies and move them around quickly. As they darken, add the cumin and garlic and stir quickly.
As soon as the garlic starts to change colour, add the onions and the red or green pepper and stir-fry for about two minutes until softened. Then add the fried chicken, salt, sugar, red chilli powder and cumin and continue stir-frying on a high heat for 1-2 minutes. Finally, add the soy sauce and mix well.
When all the vegetables are softened and the spices well combined, add the cornflower paste and stir quickly to mix evenly. This gives the dish an attractive glaze and also thickens the sauce. Squeeze in the lemon juice, add the chopped wild garlic or spring onions and stir to mix.
Serve immediately with steamed rice or noodles if serving as a main, or with a simple salad of watercress as a starter. Alternatively serve on skewers as party food or to go with cocktails.