Lay the tofu on a cutting board and cut horizontally into 8 equal slices. Put in a shallow dish with the onion, garlic, olive oil and half of the orange juice and turn to coat; marinate 5 to 10 minutes.
Meanwhile, peel the jicama using a sharp knife and cut into sticks. Toss in a bowl with the remaining orange juice and the chili powder.
Heat a large nonstick skillet over medium-high heat. Turn the tofu to coat, add to the pan and cook until golden, 3 minutes per side. Transfer to a plate. Add the marinade to the pan and cook, stirring, 4 minutes.
Spread the cut sides of the rolls with the mustard and sprinkle with the cheese. Sandwich with the peppers, pickle, onion mixture and tofu.
Heat a large cast-iron skillet over medium heat. Working in batches, add the sandwiches and top with another heavy skillet to flatten; cook until golden brown and the cheese melts, 2 to 3 minutes per side. Serve with the jicama sticks.