Rehydrate 5.3 oz/150 g tofu skin according to the instructions on the package (or soak for 30 minutes in boiling water if there aren’t instructions).
While the tofu skin is rehydrating, prepare the marinade by adding 1/2 cup beet juice, 1/2 cup cold water, 2 tablespoons soy sauce or tamari, 1/2 teaspoon garlic powder, 1/2 teaspoon onion powder, 1/4 teaspoon dried rosemary, 1/4 teaspoon dried thyme, and 1/8 teaspoon black pepper to a sheet pan. Mix well.
Transfer the rehydrated tofu skin to the sheet pan (discard any soaking water) and toss to fully coat it in the marinade, then arrange evenly in a layer in the pan (some overlap is fine).
Cover the sheet pan with aluminum foil, then let it marinate for 30 minutes at room temperature.
When it’s finished marinating, preheat the oven to 350 degrees Fahrenheit, then bake, covered, for 30 minutes.