Heat oil in a heavy-bottomed pot or pressure cooker over medium heat.
Add mustard seeds and wait for them to splutter.
Immediately add dried red chilies, curry leaves, asafoetida, and crushed garlic. Sauté for 2 minutes.
Add turmeric powder, red gram dal, quartered tomatoes, crushed peppercorns, green chili, tamarind pulp, and salt.
Mix all ingredients well and add 2-3 cups of water (2 cups for pressure cooker, 3 cups for open cooking).
Bring the mixture to a boil, then reduce heat and simmer until dal is tender and soft.
Garnish with fresh cilantro and serve hot.