Gujarati Dal - the flavors of this are a delicate balance of spicy, sweet and sour.
It is said that the longer the dal is boiled, the better it is. So if you want your flavors to be really well integrated, boil the dal for longer. Kokum is available at Indian stores and online. But if you don’t have it on hand and want to make this dal, it is no problem. You can substitute lemon juice, tamarind or even tomatoes. If using lemon juice, add 2 tbsp of lemon juice at the end after you’ve turned off the heat. If using tamarind, soak a 1 inch sized ball in 1/4 cup of warm water for about 20 minutes. Add this water to the dal after the dal with the ginger and green chilies. You can also use tomatoes, but try to use some that are tart (as opposed to sweet ones like Roma). Add about 1/2 cup of chopped tomatoes to the dal when you add the ginger and green chilies.