2pounds fresh tomatoes, cored and chopped, or 1 28-ounce can whole or diced tomatoes, including the juices
1 1/2pounds potatoes (any kind), peeled and cut into 1/2-inch cubes
1 1/2cups coconut milk, stock, or water, plus more if needed
2 tablespoons fresh lime juice
Chopped fresh cilantro for garnish
Instructions
Peel the eggplant if the skin is thick or the eggplant is less than perfectly firm. Cut into 1/2-inch cubes and salt if you like and time allows. Rinse and pat dry with towels.
Put the oil and mustard seeds in a large skillet over medium heat. Cook until the seeds begin to pop, about 2 minutes. Add the cayenne, turmeric, coriander, cumin, ginger, and garlic and cook, stirring occasionally, until the ginger and garlic soften, 3 to 5 minutes.
Add the tomatoes, potatoes, eggplant, and coconut milk and sprinkle with salt and pepper. Adjust the heat so the curry bubbles gently. Cover and cook, stirring once or twice, until the potatoes are nearly tender, about 30 minutes.
Uncover and turn the heat back up to medium; add more coconut milk or water if the mixture is dry. Cook, stirring occasionally, until both the eggplant and potatoes are very tender, about 15 minutes more. Stir in the lime juice, and taste and adjust the seasoning. Garnish with cilantro and serve.