Add 1 tablespoon olive oil to a large saucepan and place on the heat. Add the diced onions and garlic and cook on a medium heat for 2-3 minutes stirring regularly.
Next add the red lentils and coat them in the oil and onions
Stir in the turmeric, cumin and chilli flakes and then pour in the 2 cans of coconut milk and the chopped tomatoes
Bring to the boil and then reduce the heat to a simmer and leave to cook for around 15-20 minutes until the lentils are nice and soft and the dahl is thick
Remove from the heat and add in the juice of the lemon, season to taste and then leave to cool
Once cooled, portion out into 4 tupperware tubs and top with chopped coriander and additional chilli flakes
To reheat, simply place in the microwave in the Tupperware for around 2 minutes until piping hot. Serve with a pitta bread