This is my version of the spicy squash, eggplant, and lentil stew from Suvir Saran's cookbook, Indian Home Cooking.
Put the split peas and lentils in a large soup pot with 4 1/2 cups of water. Bring to a boil. Add the garlic, ginger, garam masala, turmeric, cayenne, cloves, bay leaves, chilies, and salt. Turn the heat down and simmer, covered, until the legumes are tender, but not falling apart, about 20 minutes. Stir occasionally to prevent sticking.
Add the tomatoes, butternut squash, eggplant, onion, corn, and spinach, and 2 more cups water. Bring the stew to a boil, turn the heat down, and simmer, covered, for about 15 minutes. Take the stew off the heat.
In a medium frying pan, heat the coconut oil with the mustard seeds, and cook 1-2 minutes, until the mustard seeds start to pop and crackle. Add the chopped onion and cumin and stir constantly, until the onion is browned on its edges, about 4 minutes. Turn the heat to medium, add the garlic, and cook for a few seconds. Stir in the cilantro. Add the lemon juice, and remove the frying pan from the heat. Scrape this final flavor layer into the stew.
Taste and adjust for salt and consistency. If stew is too thick add a few tablespoons of water.