Cover masoor lentils with water and soak for 20-25 minutes.
Prep vegetables. Slice onion, dice tomato and chop green chili pepper.
Keep spices ready at the side.
Heat up a pan with olive oil, temper mustard seeds for 1 minute or until you can smell the nutty aroma. (mustard seeds will pop up so be careful and control the heat/use a lid)
Sautee onion, tomato and green chili pepper.
Strain soaked lentils. Keep a slow heat setting and stir soaked lentils and tomato sauce to the pot.
Season with curry leaves ginger+garlic, turmeric powder, cayenne pepper powder, and salt.
Pour stock over the lentils and increase heat setting to medium-high. Stir to combine ingredients.
Cook on medium to high heat for about 15 mins, stirring occasionally so that nothing burns on. If you feel your masoor dal needs more water, then just add a little more to adjust the curry consistency (sometimes depends on the quality and age of the lentils).
The dish is ready when the lentils are cooked, but not mushy.
Garnish with chopped fresh cilantro (Coriander)
Notes
For the Ginger + Garlic, use ginger garlic paste or chop ⅓ ginger and ⅔ garlic fine.
You need to use black mustard seeds (never the yellow mustard seeds) and add curry leaves (and not curry powder as it's something completely different). Don't omit these ingredients, they make this curry amazing!