Heat 2 tablespoons oil in a kadhai or pan over medium heat. Add mustard seeds and let them splutter, then add cumin seeds and asafoetida.
Add chopped onions and saute until they turn golden brown, about 5 minutes.
Add ginger&garlic paste and saute for a minute until the raw smell disappears.
Add chopped tomatoes and cook until they become soft and mushy, about 4 minutes.
Add red chilli powder, turmeric powder, coriander powder, goda masala, and salt. Mix well and cook the masala for 2 minutes.
Add the sprouted moth beans and mix everything together. Add 1 cup water and bring it to a boil.
Lower the heat and simmer for 15 to 20 minutes until the beans are cooked through and the mixture thickens. Mash a few beans with the back of your spoon for a thicker consistency.
Garnish with chopped coriander leaves and set aside. The usal should be thick, not watery.
Prepare the Misal Masala and Rassa
Heat a dry pan and roast Kashmiri red chillies, regular red chillies, coriander seeds, cumin seeds, black peppercorns, cloves, cinnamon, and black cardamom until fragrant, about 2 to 3 minutes. Do not burn them.
Add desiccated coconut to the same pan and roast for another minute until lightly golden. Let everything cool down.
Grind the roasted spices and coconut to a fine powder using a mixer grinder. Set aside.
Heat 1 tablespoon oil in a pan. Add sliced onions and saute until they turn golden. Add ginger and garlic, saute for a minute.
Add chopped tomatoes and cook until soft, about 3 to 4 minutes.
Add the ground misal masala powder, turmeric powder, and salt. Mix well and cook for 2 minutes.
Add 3 cups water and bring the mixture to a boil. Lower the heat and simmer for 10 minutes. The rassa should be thin and pourable like a spicy soup. Strain if you want a smoother consistency.
Assemble the Misal Pav
Take a serving bowl and add 2to3 tablespoons of prepared usal at the bottom.
Pour hot rassa (tarri) over the usal, enough to cover it.
Top generously with farsan or sev, chopped onions, chopped tomatoes, and fresh coriander leaves.
Squeeze fresh lemon juice on top and serve immediately with pav on the side. You can toast the pav with butter on a tawa if desired.
Notes
Sprout the moth beans by soaking them overnight, draining the water, and keeping them covered in a damp cloth for 1 to 2 days until small tails appear.
You can make the usal and masala powder in advance and store them separately. The usal stays fresh in the fridge for 3 to 4 days.
Adjust the spice level by increasing or decreasing the number of red chillies in the masala.
For a richer rassa, you can add 1to2 tablespoons of peanuts while grinding the masala.
Goda masala is a traditional Maharashtrian spice blend. If unavailable, use garam masala but the flavour will be slightly different.
Always add the toppings just before serving to maintain their crunch and freshness.
If the rassa becomes too thick, add more water and bring it to a boil again.