Heat the oil in a large pan and fry the onion and garlic for a minute over a high heat. Stir in 3 tbsp curry paste and sizzle for another minute, then add the rinsed lentils and 1 tin chickpeas.
Pour in the coconut milk, then fill the tin with water and add that, too.
Bring to the boil and cook for about 30 minutes until the lentils are just done.
Stir in the spinach to wilt, season and add the lemon juice. Serve with plain naan.
Recipe by The Knobbly Plate at http://theknobblyplate.co.uk/?p=380