
Add the oil to a large pot on high heat. Add the onion, garlic, and ginger. Cook for 5 minutes, then add cumin seeds and stir for about 30 seconds.
Add the tomato paste, cumin powder, coriander, salt, and turmeric. Stir to combine.
Add the broth and the moong dal. Bring to boil, then reduce to simmer and cover for 30 to 40 minutes until the moong dal is soft.
Remove from heat.
Top with the red onion slices and cilantro if desired and serve in individual bowls.