Preheat the oven to 375F and line a baking sheet with parchment.
In a bowl, add the the tamari or soy sauce and miso and use a fork to mash and mix the miso into the soy sauce so that it dissolves. Stir in the maple syrup, rice vinegar, garlic and red pepper flakes. Add the tempeh and toss gently to coat. Let it marinate for at least 20 minutes.
Transfer the marinated tempeh to the baking sheet, reserving as much marinade as you can, and spread in an even layer so they aren’t touching. Bake for 10-15 minutes, or until caramelized.
Serve immediately drizzled with the remaining marinade. I love it in a rice bowl or on top of a veggie stir-fry.