Cook toor dal in a pressure cooker until very soft and mushy. Keep aside.
In a medium sauce pan, heat 2tsp oil, add the tempering ingredients in the order listed and once the seeds start to splutter, add onions and green chilies. Sauté until onions are translucent.
Next add chopped tomatoes, cover and cook till they turn mushy.
Next add the chopped sorrel spinach and cook till the leaves wilt.
Add red chili powder and salt.
Finally add the cooked dal, mix well and simmer for 3-4 minutes for the flavors to mingle. Add water if dal seems too thick while cooking.