For a quick curry what I generally do is marinate the diced chicken in garlic, ginger, chilli, coriander-cumin powder, tumeric, garam masala and lemon juice for at least a few hours (preferably a day) before using the typically bland store-bought paste recipe.
Fry chopped onion and optionally chopped red pepper in veg. oil for a minute or two. Add Patak's curry paste (Rogan Josh is good) and heat for a bit more. Add stock, and a bit of apple sauce and a handful of sultanas. Simmer for 20 minutes, stirring regularly.
If the chicken you're using is raw, add chunks of it immediately after you've poured in the stock. If you're using leftover cooked chicken, add it five minutes before the end.
A couple of minutes before the end, add a couple of ounces of ground almonds - it thickens the curry and adds a subtle nutty flavour. A tablespoon of natural yoghurt and/or a bit of creamed coconut is also good.
Serve with rice.
Had a curry like this tonight as it happens - YUM. And I've written a hub extolling the virtues of Patak's pastes if anyone's interested.