In a large saucepan cook corn, covered, in boiling salted water for 7 minutes. Drain.
Meanwhile, slice each block of tofu horizontally into four slices. In a shallow dish combine cornmeal, chili powder, and salt; dip tofu into mixture to coat.
In a 12-inch skillet heat 1 tablespoon oil over medium-high heat. Cook tofu in batches for 2 to 3 minutes per side until crisp and golden brown, adding more oil as needed. Remove tofu from skillet. Add sweet pepper and green tomatoes to remaining oil in skillet; cook about 3 minutes until tomatoes are heated through and lightly browned and pepper slices are crisp-tender.
Cut corn from cobs. Place one slice of tofu on each of four serving plates. Top with half of the corn, pepper slices, and tomato slices. Top with remaining tofu slices and remaining corn, pepper, and tomatoes. Serve with lime wedges and fresh cilantro leaves, if desired.