Ingredients

1. 1/2 cup thoor dhal or yellow split peas (3 1/2 ounces), rinsed in several changes of water
2. 3 1/4 cups water
3. 1/4 teaspoon turmeric
4. 2 tablespoons vegetable oil
5. 1/4 teaspoon fenugreek seeds
6. 1/8 teaspoon asafetida
7. 1/4 pound okra, trimmed
8. 1 medium boiling potato, peeled and cut into 3/4 -inch dice
9. 1 medium tomato, coarsely chopped
10. 1 medium onion, coarsely chopped
11. 1/4 cup cilantro leaves
12. 1 serrano or Thai chile, cut in half lengthwise
13. 2 teaspoons ground coriander
14. 1 1/2 teaspoons salt
15. 1/2 teaspoon ground cumin
16. 1/4 teaspoon tamarind concentrate, dissolved in 1 tablespoon boiling water
17. 1/8 teaspoon cayenne pepper
18. 1/8 teaspoon freshly ground black pepper
19. 1/4 teaspoon mustard seeds
20. 8 curry leaves or 2 bay leaves
21. 1 dried red chile
22. 1/2 teaspoon fresh lemon juice

Directions

1. In a small saucepan, combine the dhal with 1 1/4 cups of water and 1/8 teaspoon of the turmeric and bring to a boil. Cover and cook over low heat until soft, about 30 minutes (45 minutes for yellow split peas). Partially mash the dhal with a potato masher.
2. Meanwhile, in a large saucepan, heat 1 tablespoon of the oil. Add the fenugreek and asafetida and cook over moderately high heat until fragrant and lightly colored, about 1 minute. Add the okra, potato, tomato, onion, cilantro, serrano chile, coriander, salt, cumin, the remaining 1/8 teaspoon of turmeric, dissolved tamarind, cayenne and black pepper along with the remaining 2 cups of water and bring to a boil. Reduce the heat to moderately low and simmer until the potatoes are tender, about 18 minutes. Add the mashed dhal and simmer 10 minutes longer. 
3. In a small skillet, heat the remaining 1 tablespoon of oil. Add the mustard seeds, curry leaves and dried red chile. Cover and cook over moderately high heat until the mustard seeds have popped for a few seconds, then stir into the vegetable and dhal mixture. Add the lemon juice and serve. 
4.  

Make Ahead

The recipe can be prepared through Step 1 up to 1 day ahead.