Cook the toor dal and keep it aside. Check my detailed post on how to cook toor dal using instant pot or pressure cooker.
While the dal is cooking, wash and drain spinach leaves. Chop them roughly and keep them aside.
Heat a pan and add oil once it is hot.Add cumin seeds, mustard seeds, and hing to the hot oil. Make sure to be a little away as seeds will splutter.
Now add red and green chili to the pan.
Once these turn lightly brown, after a minute or so, add chopped spinach to the pan.
Let the spinach leaves cook for 3 to 4 minutes.
To these wilted spinach leaves, add cooked and mashed dal.
Now add coriander powder, turmeric powder, and salt. Mix it well and let the spinach lentil curry cook for 5 minutes.
Once the spinach leaves are cooked properly, switch off the flame and add lemon juice to the spinach dal.
Mix it well, and the Spinach dahl is ready to serve!