Preheat oven to 425 degrees F.
Peel and chop the sweet potato into small, bite-sized pieces. Melt the coconut oil and drizzle it over the sweet potatoes. Toss to coat. Add in chili powder and sprinkle with salt and pepper, tossing to combine. *If using cayenne pepper, add it with this step.
Roast the sweet potatoes for 20 – 25 minutes until tender, stirring halfway through so as not to burn them.
While sweet potatoes are cooking, rinse and drain the black beans. Add them to a large bowl along with cooked quinoa. Set aside.
Add all dressing ingredients to a blender (starting with less water and adding more as needed). Blend on high until smooth and creamy. Add enough water to make it a consistency that will drizzle.
Once sweet potatoes are done roasting, let them cool for 5 minutes. Add to the bowl with black beans and quinoa. Squeeze lime juice over the top and stir to combine.
Arrange the lettuce in 4 bowls. Top with sweet potato-black bean mixture and drizzle with dressing. Enjoy as is or toss everything together in the bowls.