Heat oil in a pan and fry onion until soft.
Add garlic and ginger and cook for 1 minute.
Add curry powder, cumin, turmeric, and stir to release flavour.
Add chicken and cook until it starts to brown.
Add tomatoes (or paste) and a splash of water.
Simmer for 15–20 minutes until chicken is cooked and sauce is thick.
Season with salt and add chilli if you want extra heat.
Warm the roti or flatbread.
Spread mayo or chutney.
Add lettuce, tomato, onion, and chicken curry filling.
Roll tightly like a wrap or fold like a sandwich.
Optional: toast lightly in a pan for a crisp finish.