Jools’ easy chicken curry

Name: Jools’ easy chicken curry
Cook time: 1 h 30 min
Total time: 1 h 30 min
Cuisine: Asian, Indian
Ingredients: 1 onion; 4cm piece of ginger; 2 cloves of garlic; olive oil; 2 tablespoons tikka masala paste; 3 tablespoons natural yoghurt; 2 tablespoons tomato purée; 8 skinless free-range chicken thighs; 1 x 400 g tin of chopped tomatoes; 1 x 400 g tin of green lentils; 1 x 400 g tin of light coconut milk; 2 handfuls of baby spinach optional; 2 tablespoons quality mango chutney