1. Preheat Your Oven and Prepare Sweet Potatoes: Preheat your oven to 400 F (200 C). On a large baking sheet, spread out the diced sweet potatoes. Drizzle with 1 tablespoon of olive oil, season with salt and pepper, and toss to coat evenly. Ensure they are in a single layer for even roasting.

2. Season the Chicken: In a medium bowl, place the chicken pieces. Drizzle with the remaining 1 tablespoon of olive oil. Add the smoked paprika, garlic powder, onion powder, cayenne pepper (if using), salt, and black pepper. Toss well to ensure every piece of chicken is thoroughly coated with the spices.

3. Roast Sweet Potatoes and Chicken: Place the seasoned chicken on a separate baking sheet or alongside the sweet potatoes if your sheet is large enough and not overcrowded. Transfer both baking sheets to the preheated oven.

4. Cook Until Tender and Golden: Roast for 25-30 minutes, or until the sweet potatoes are tender and slightly caramelized at the edges, and the chicken is cooked through with an internal temperature of 165 F (74 C). You might want to flip the sweet potatoes halfway through cooking for even browning. The chicken should have a nice golden-brown crust.

5. Rest and Slice the Chicken: Once cooked, remove the chicken from the oven and let it rest on a cutting board for 5 minutes before slicing it into bite-sized pieces or strips. This helps keep the chicken juicy.

6. Assemble Your Bowls: Divide the mixed greens among serving bowls. Top with the roasted sweet potatoes, sliced chicken, and thinly sliced red onion.

7. Garnish and Serve: Garnish each bowl with fresh chopped cilantro. Drizzle with your favorite dressing just before serving. Enjoy immediately!