Put the split peas in a pressure cooker with the water, fenugreek leaves, tomato, onion, turmeric, chile, peppercorns, butter, and ginger, and cook until done (about 4 whistles).
Heat the ghee in a pan, add the mustard seeds, cumin, garlic, dried chiles, and curry leaves, and fry until the garlic is golden.
Add the chopped tomato, salt, chile powder, and ground coriander to taste.
Pour the cooked lentil mixture into the fried spices, and bring to a boil together; add a little water if you'd like it thinner.