To make the dahl, place the lentils (Chana dal) in a solid steam container with enough water to cover and steam in a steam oven for 25 minutes at 100°C.
In the meantime, heat the oil in a frying pan over a medium heat with the cumin seeds. When the seeds start to pop, add the onion and red chilli and cook until soft and translucent (this should take around 10 minutes). Add the remaining spices and cook for another 2 minutes then add the cooked lentils to the pan and combine. Season to taste and add a little water to loosen if required.
For the bhaji, place the white onions on some kitchen paper to absorb as much moisture as possible. Mix the remaining ingredients together to achieve a smooth paste. Add the sliced onions and mix well.
Pre-heat a large frying pan with some vegetable oil on a medium heat and add a tablespoonful at a time of the mixture and cook the bhaji for about a minute per side. Once cooked, place on some kitchen paper and keep warm until needed.
For the cauliflower, mix the florets with some vegetable oil, salt and pepper and place on a baking tray. Transfer to an oven and roast on the fan setting at 180°C for 30 minutes.
To serve, spoon the dahl onto the plate and garnish with the bhaji, roasted cauliflower, yoghurt and coriander.