Let's slice 1 8-oz. package of tempeh (any kind you like, plain, with flax seeds, 5-grain etc.) into thin rectangles and steam for 15 minutes. Remove the tempeh and allow it to cool to room temperature. Place it in a zip-lock bag along with: 1/2 cup red wine or cider vinegar, 2 T. tamari or soy sauce, a large pinch of sugar, a very large pinch of cayenne pepper and 1 T. olive oil. Seal the bag, agitate it gently to combine all the ingredients and allow the tempeh to marinate at room temperature, still sealed, for 1 hour. If you wish to marinate longer, such as overnight, refrigerate.
Lightly oil a baking sheet and preheat your oven to 375 degrees F. Roast the tempeh in a single layer on the baking sheet for about 25 minutes. Flip the slices once, halfway through cooking.
While the tempeh is roasting make the sauce by heating 1 T. olive oil in a deep skillet over medium heat. Add 1 cup diced onion, 1 small orange bell pepper (roughly chopped) and 2 cloves of minced garlic. Cook for a few minutes or until the veggies are soft. Add 1 24-oz. can of whole tomatoes, crushing a bit with your hands as you drop them in the skillet. Pour in all the juice as well.
Season to taste with salt and black pepper. Stir in 3 T. brown sugar, the juice from 1 orange, 1 T. orange zest, 2 T. balsamic vinegar and 1/2 t. ground cinnamon. Cook for 20 minutes, uncovered, until the sauce thickens and the tomatoes begin to break down. Taste and adjust seasoning if required.
Finally, assemble it all, enjoying the roasted tempeh with the warm tomato sauce with brown rice, quinoa, garlic bread or over your favorite pasta.