If cooking the brown rice from scratch, start cooking it first. If not, skip to the 2nd step.
Preheat the oven to 425F (218C). Line a baking sheet with parchment paper or a silicone mat.
Peel (optional) and chop the sweet potato, in small cubes (1 1½ inch / 2 cm approx). In a bowl, toss the cubed sweet potatoes with salt, pepper, cumin and paprika to taste. Transfer to the lined baking sheet, spread evenly so they’re not touching each other, and bake for 20 minutes.
Cube the tempeh and transfer to a bowl.
*Optional step:* Boil or steam the cubed tempeh for a few minutes, about 3 to 5. This gets rid of the bitterness and yields a more pleasant taste. I would recommend this step if you are new to eating tempeh.
Mix the cubed tempeh with liquid soy seasoning, garlic powder, chili powder, onion powder, cumin, salt and pepper. Sauté in a pan until golden brown and cooked throughout. Use water/vegetable broth as needed if it starts to stick. Monitor the heat closely.
Cook the brown rice at this point if using pre-cooked brown rice, according to package instructions.