Turn the slow cooker on.
Heat the oil in a frying pan over a medium heat and sauté the onion for 5 minutes until starting to soften and colour. Stir in the garlic, dried spices and tomato purée. Cook for 1 minute then pour in the stock and bring to the boil.
Put the chicken, lentils, pepper, potato and tomatoes in the slow cooker dish, and pour over the hot stock and spiced onions. Mix everything together and season with salt and freshly ground black pepper. Cover with a lid and cook for 4 hours on high or 8 hours on low until the chicken is cooked through with no pink showing.
Serve with basmatti rice or naan bread and mango chutney.
See more Indian recipes
For top tips on protecting you and your family when preparing raw meat and poultry, visit Food Safety in the Home and view the full Food safety at home video.