1. Soak the lentils together for 3 hours
2. Bring both the black lentils and yellow lentils to the boil in salted water, adding a splash of oil and boil until they are tender and soft for approximately 2 hours,
3. Melt around 4 oz butter with a dash of oil in a casserole, adding the ginger and garlic paste, red chilli powder, cumin powder and tomato puree and sauté until the oil separates. The masala leaves the vessel and the oil oozes out.
4. Add the boiled lentils to the casserole and toss well with Garam masala powder. Add the fenugreek leaf powder, remaining butter and cream.
5. Add the garam masala and simmer until the dal reaches a smooth consistency.
To Garnish:
Add a knob of chilled butter when serving that will melt into the dal.