Spray a non-stick frying pan with oil, and heat over medium-low heat. Add the onion and cook, stirring often, for 5 minutes or until soft.
Increase heat to medium-high, and add the chicken. Cook, turning occasionally, for 4 minutes or until golden. Add the curry paste and cook stirring, for 1 minute.
Add stock, tomatoes and lentils. Bring to the boil. Reduce heat to low and simmer for 20-25 minutes, or until lentils are tender. Stir in cream and cook for about 1 minute or until heated through.
Lightly spray the pappadams with oil and cook on a sheet of paper towel in the microwave for 45 seconds or until puffed.
Divide the curry between dishes and serve topped with the coriander leaves, with pappadams on the side.