Boil the lentils till tender and set aside.
In a deep pan, heat oil and add in the cumin and fennel seeds. Once they starts to sizzle, add in the onions, chillies, garlic and ginger.
Fry of a few minutes till onions lightly brown, before adding in the turmeric and chilli powder. Give it a quick stir and add in the tomatoes. Once the tomatoes start to soften, add in the cooked lentils and about 1-2 cups of water, depending on the consistency you prefer.
Season with salt, and let the Dal simmer for a few minutes to allow all the flavours to blend.
Garnish with fresh cilantro and serve warm.