To make the salad, put the tempeh in a shallow glass bowl or container, preferably one large enough tofit all of the tempeh in a single layer. In a small bowl or measuring cup,whisk together the tamari, vinegar, maple syrup, and paprika. Pour the mixture over the tempeh and stir gently to evenly coat the cubes. Cover and refrigerate for at least 1 hour and up to 12 hours.
Preheat the oven to 400°F (200°C) and line two rimmed baking sheets with parchment paper.
In a large bowl, toss the sweet potatoes with the oil until evenly coated. Transfer to one of the lined baking sheetsand sprinkle generously with salt and pepper. Bake for 30 to 35 minutes, until fork tender and starting to brown.
Meanwhile, drain the tempeh and spread it on the other lined baking sheet. Bake for 15 minutes, untilthe tempeh is beginning to brown. Transfer the sweet potatoes and tempeh to a large bowl and let cool for about 10 minutes. Add the arugula.
To make the dressing, combine the oil, maple syrup, mustard, tamari, apple cider vinegar, balsamic vinegar, and nutritional yeast in a small bowl or measuring cup. Whisk to combine. If the dressing is thicker than you’d like, whisk in the warm water as needed. (Stored in an airtight container in therefrigerator, the dressing will keep for 1 week.) Pour the dressing over the salad and toss gently to combine. Fold in any additional toppings and serve.