Drain the tofu, blot with a paper towel and cut into bite sized cubes.
Mix the curry powder and half the lime juice in a large bowl. Add the tofu cubes and toss. Let marinate for a least an hour.
Heat 2 oz of the oil in a skillet, add the tofu and cook over medium-high heat until brown. Then turn off heat, add the remaining lime juice and set aside.
Heat the remaining oil in a skillet with the cumin seeds. When hot, add the onions and saute over high heat until they're lightly brown. Add the green peppers, garlic, ginger, cayenne, coriander and turmeric. Cook some more minutes until the peppers have softened somewhat.
Add the tofu and tomatoes and cook until the tofu is heated through. Add the cilantro and serve.