Empty 1 tin of sweetcorn and its liquid into a blender, add 550 ml water and blend until smooth.
Heat 1½ tablespoons of the oil in a saucepan over a medium heat and sauté the onion for 3 minutes, until soft and translucent.
Add the garlic and cook for 30 seconds more.
Add the ground spices and cook for 30 seconds, then stir in the lentils, frozen spinach, the blitzed sweetcorn stock and the remaining tin of sweetcorn and its liquid.
Bring to the boil then lower the heat and simmer gently for 15–20 minutes, or until the lentils are soft.
Add a dash of water if the dhal becomes too thick.
Season generously with salt and pepper.
Just before the dhal finishes cooking, heat the remaining olive oil in a small frying pan and add the cumin seeds and curry leaves (if using).
Fry over a low–medium heat for about 1 minute, or until the seeds start to pop.
Pour over the dhal, stir to combine and serve.
