Preheat the oven to 425°F then line a baking sheet with parchment paper. Arrange the diced sweet potato on top and bake in the oven for about 20-25 minutes, until tender, stirring halfway through.In a small pot, bring 3 cups water to a boil. Add the farro and cook for about 20 minutes, until tender. Once all of the water has absorbed, add the turmeric and stir to combine.In a large pot, warm the olive oil over medium heat. Add the onion and cook for 3 minutes. Add the mushrooms, sprinkle with salt & pepper and garlic powder, then cook for about 5 minutes, until the mushrooms release their liquid. Lastly, add the kale and cook for about 5-7 minutes, until wilted.In a large bowl. whisk together the miso, tamari, rice wine vinegar, pure maple syrup and 1/4 cup water until smooth. Add the sweet potatoes to the bowl and toss until evenly coated. Arrange the sweet potatoes in separates bowls with the farro and the kale/mushroom mixture. Top with avocado and tahini sauce (optional, see notes), and enjoy!