Prepare cashew cream - place drained cashews and juice of 1 lime into a blender. Puree until smooth, adding a little fresh water as needed until creamy and smooth. Add salt to taste, about 1/4 teaspoon. Transfer to a bowl and refrigerate until ready to use. (You will have more than is needed for this recipe. Leftovers will keep for a few days in the fridge, or several months frozen.)
Preheat oven to 425°F. Line a baking sheet with parchment paper. Toss the sweet potato cubes with a little of the coconut oil (melted, if solid) and season well with salt and pepper. Arrange in a single layer on the baking sheet lined with parchment paper. Roast for 20-25 minutes. Keep warm until ready to add to other ingredients.
While sweet potatoes are roasting, remove outer leaves and core from cauliflower. Roughly chop. Working in batches if needed, place cauliflower in food processor or blender and pulse until finely chopped, but not pureed.
Heat the remaining coconut oil in a large skillet. Add the diced onion and cook over medium heat until softened, about 5-10 minutes. Add the chili powder and cumin. Cook for another 30 seconds or until fragrant. Add the cauliflower and cook, stirring often to prevent burning, for 10 minutes or until just cooked through. If it starts to stick to the bottom, add a little bit of water, but not too much. Add the black beans and roasted sweet potatoes; stir to combine.
Remove from heat and squeeze lime juice over the top. Spoon out onto plates and add a dollop of cashew cream on top and sprinkle with cilantro.