Soak the horse gram for 8-10 hours or overnight in water.
½ cup horsegram
After the soaking hours, add drained horse gram, sambar onions, tomatoes, garlic, ginger, pepper, jeera, coriander leaves, salt and water to a pressure cooker.
6 sambar onions, 1 tomato, 3 garlic cloves, 1 teaspoon chopped ginger, 1 teaspoon pepper, 1 teaspoon jeera, ¼ cup fresh coriander leaves, ¾ teaspoon salt, 1 ½ cups water + extra
Pressure cook on high and after the first whistle, cook for 20 more minutes on low heat.
Let the pressure release naturally. Horse gram has to be cooked so well that it can be easily mashable. Cool the mixture and blend till smooth.
To make tadka, heat ghee in a pot large enough to hold the soup. Add sambar onions, curry leaves, garlic and whole red chillies. Saute for a minute or two till the onions start to brown. Pour the soup over this. Check for seasoning and serve topped with coriander leaves and drops of olive oil.
2 teaspoons ghee, 2-3 sambar onions, 1 sprig curry leaves, 4 unpeeled garlic cloves, 2 whole red chillies, 1 tablespoon finely chopped coriander leaves, 1 teaspoon olive oil