Chicken tikka can be used as a starter, or as an ingredient, either in a more complex curry such as a chicken dhansak, or as a pizza topping (with green chillies and pieces of fried onion). Try it as a sandwich filling, too. If being used as a sandwich filling or pizza topping, you probably want to cut the pieces up much smaller than if you're using it as a starter or in another curry.
Mix the diced chicken breast with the dry spices and lemon juice, and leave to marinade for at least an hour, stirring after half an hour.
Now, mix in the remaining ingredients well, and leave to marinade for about 2 hours, stirring every half hour or so.
Preheat the oven to 200 degrees C / 400 degrees F / Gas Mark 6.
Place the marinated meat on skewers or a grill (using skewers makes the pieces easier and quicker to retrieve) and put the grill onto a tray, or the skewers across a tray to catch the drips. Drizzle the chicken with a little oil if desired, then place in the preheated oven for about 15 minutes. The meat should be very tender, basically falling apart when it is ready.
If serving as a starter, sprinkle some chopped fresh coriander over it. If not being used straight away, place in a dish when cool, cover the dish with cling film and place in the fridge; it should keep for a few days.