Heat half of the oil in a large pan and add the onion and pepper. Cook gently for 8-10 mins, until softened. Stir in the garlic and ginger and spices, and cook for 1 - 2 mins more.
Add the remaining oil and the chicken, and cook for 2-3 mins until coated in the spice mixture. Stir in the stock and lentils, bring to the boil then cover and simmer for 25 mins, stirring occasionally until the lentils are tender and the chicken is thoroughly cooked.
Stir in half the yogurt and cover; simmer for a further 5 minutes.
Spoon the curry into individual bowls with basmati rice, and top with the remaining yogurt and a sprinkling of almonds.