Tofu brings the protein to this recipe, and the vegetables are grilled just until al dente, so they retain a nice firm texture and bite. The toppings here—with spicy, herbal, and acidic notes—make the dish really sing.
Preheat a grill to very high (500°F). Sprinkle tofu slices evenly with chipotle chile powder, 1 teaspoon salt, and 1⁄4 tea- spoon cumin. Drizzle with 1 tablespoon oil. Toss together bell peppers, onion, corn, and 1 tablespoon oil in a large bowl.
Place bell peppers, onion, and corn on oiled grates; grill, covered, until grill marks appear, about 4 minutes per side. Remove from grill. Grill tofu, uncovered, until grill marks appear, about 3 minutes per side. Grill tortillas until pliable and slightly charred, about 15 seconds per side.
Slice grilled bell peppers, and coarsely chop onion; place in a large bowl. Remove corn kernels from cob. Add corn kernels, lime juice, black pepper, remaining 3 tablespoons oil, remaining 1⁄2 teaspoon salt, and remain- ing 1⁄4 teaspoon cumin to bell pepper mixture; toss to combine. Cut each tofu rectangle in half diagonally to form 24 triangles total.
Divide grilled vegetable mixture among tortillas. Top each tortilla with 2 grilled tofu triangles and about 1⁄2 tablespoon sour cream. Top with hot sauce and cilantro, and serve with lime wedges.