Heat a heavy based large saucepan and spray with the oil spray. Add the onion, garlic and chilli cook gently until softened.
Now add the Chicken pieces and cook for a further 5 mins.
Add the garam masala, tomatoes and lentil soup to the chicken. Stir and reduce to a simmer.
Cook for a further 20 minutes until the sauce has thickened or transfer to a slowcooker and cook as per your slowcooker instructions - normally 2-3 hours on low
Stir in the fresh coriander just before serving. Serve with basmati rice or a naan bread (calories for these are not included)