To start, finely chop the garlic and ginger and put them in a bowl. Then chop half of the onion and cut the tomato into small diced pieces. Combine with the garlic and ginger.
In a small pot, heat some olive oil then add in the vegetables. Let it sit until it looks like a paste, stirring frequently to avoid it sticking to the pot. Then add in the lentils and mix it around with the paste to absorb the flavor. Stir around for another 2-3 minutes then add in the water, cover and let simmer.
Here’s a useful trick, instead of continuously adding water to avoid the lentils from drying out, pour some water into a bowl (preferably a stainless steel bowl) and place it directly over the pot. The sweat from the evaporation will keep the lentils moist. Using a small skillet, toast the black peppercorn, cumin seeds and mustard seeds until you hear popping. Remove from heat and transfer to a coffee grinder or mortar and pestle to roughly grind the spices. I eyeballed it to be exactly 2t combined. The toasting of the spices really intensifies the fragrance.
Halfway through, add in all of the spices and salt. Taste test. If the lentils aren't done yet, just let it simmer with the bowl of water on top for evaporation.