Preheat oven to 400°F and line a baking sheet with parchment paper or a silicone mat. Arrange potatoes, cabbage and tempeh on top then spray with high heat oil. Bake in the oven for 15 minutes.
Meanwhile, prepare the marinade in a large bowl by whisking together 2 tablespoons tamari, 2 tablespoons red wine vinegar, 1 teaspoon dried oregano and 1 teaspoon smoked paprika.
In a separate small bowl (or measuring cup) prepare the dressing by whisking together ¼ cup tahini, 2 tablespoons red wine vinegar, 2 tablespoons mustard, 1 minced garlic clove and ¼ teaspoon salt. Add a tablespoon of water at a time to thin. I used about 4 tablespoons of water for mine. Add more vinegar, mustard or salt, to taste.
Remove pans from the oven and set aside. Using tongs, carefully transfer the tempeh to the bowl with the marinade. Toss until evenly coated then set aside.
On the sheet pan, carefully flip the potatoes and cabbage pieces over. Toss the tempeh once more then transfer it back to the baking sheet. Bake in the oven for 15 minutes, until everything is cooked through.
Serve warm topped with tahini dressing and chopped parsley then enjoy!