In a large mixing bowl, whisk together all of the marinade ingredients.
Add the chicken.
Mix well to ensure that all of the chicken pieces are well coated.
Cover the bowl with cling film and leave to marinate in the fridge for at least 30 minutes, 3 hours if you have time, or overnight is best.
To Cook the Chicken
Heat some oil in a large non-stick pan over medium-high heat.
Cook the chicken in batches until they are lightly brown all over. The chicken pieces do not need to be cooked through completely at this stage.
Alternatively, line a large baking tray with foil, and spread the chicken evenly over the tray. Place in the oven under a hot grill (250°C/482°F) (without fan) and cook until the chicken is lightly brown all over. This will take about 10 to 15 minutes, but the timing will vary depending on how hot your grill is. I especially recommend this method if you are cooking a double or triple portion of this recipe.
To Cook the Butter Chicken
Heat some oil in a large skillet or pan.
Sauté the onions and garlic for a few minutes until they have softened.
Add the remaining sauce ingredients. At this stage, the sauce will look pink in colour.
Let the sauce simmer gently for a few minutes.
Add the cooked chicken pieces to the sauce and give everything a good stir. The marinade from the chicken will start to mix with the sauce to give a nice golden colour.
Simmer on low-medium heat for about 30-45 minutes, stirring occasionally.
Taste for seasoning.
To Serve
Sprinkle the Butter Chicken with coriander (cilantro) just before serving.
INSTRUCTIONS FOR SLOW COOKER * Follow the same instructions as for the stove top. * Cook on low (95°C/203°F) for 4-5 hours or high (105°C/221°F) for 3-4 hours.
MAKE IT CHILD-FRIENDLY Omit or reduce the ground chillies, and maybe serve some Pickled Chillies on the side for the adults.
PICKLED ONIONS A condiment which I find obligatory to serve alongside Butter Chicken is Pickled Onions. Simply slice 2-3 red onions into half moons, and cover them with lime juice (fresh or bottled). Leave to steep for at least a few hours at room temperature, or overnight in the fridge. The onions will soften as they steep, and the lime juice will turn bright pink from the onions.
OVEN & STOVE TEMPERATURES All recipes on this website have been tested on an induction stove and/or with a conventional oven (i.e. an oven without fan). All recipes on this website use temperatures for a conventional oven, unless otherwise mentioned. Convection ovens (i.e. fan-forced ovens) are typically 20°C/70°F hotter than conventional ovens, but please check your manufacturer's handbook.