4 ounces tempeh
1 tablespoon tomato paste
1/4 teaspoon dried oregano
Salt
Freshly ground black pepper
1 tablespoon olive oil
1 French or submarine sandwich roll
2 tablespoons marinara sauce
1 tablespoon shredded Parmesan cheese
1/2 cup shredded mozzarella cheese
Arrange a rack in the top third of the oven and heat to broil. Line a baking sheet with foil and set aside.
Depending on the thickness and shape of the tempeh, cut it into pieces as needed so that it is about the same size as the sandwich roll. (You may need to butterfly the tempeh in half.) Brush one side of the tempeh with the tomato paste. Sprinkle with the oregano and season with salt and pepper.
Heat the oil in a small nonstick frying pan over medium heat until shimmering. Add the tempeh and cook until golden-brown, 2 to 3 minutes on each side. Remove the pan from the heat.
Split the sub roll in half lengthwise. Place directly on the oven rack cut-side up and toast until light golden-brown, 1 to 2 minutes (keep a close eye on it). Transfer the roll cut-side up to the baking sheet. Place the tempeh on the bottom half of the roll. Spoon the marinara sauce evenly over the tempeh, then sprinkle with the Parmesan. Sprinkle the mozzarella evenly over the top half of the roll.
Broil until the mozzarella is melted, about 2 minutes (keep a close eye on it). Close the sandwich, cut in half crosswise with a serrated knife, and serve.