Preheat the oven to 425°F (220°C).

In a mixing bowl, toss the diced sweet potatoes with olive oil, salt, and black pepper.

Spread the sweet potatoes on a baking sheet in a single layer.

Roast in the oven for 25-30 minutes, or until tender and slightly caramelized, stirring halfway through.

While the sweet potatoes are roasting, preheat a grill or grill pan over medium-high heat.

Brush the chicken breasts with BBQ sauce on both sides.

Grill the chicken for 6-7 minutes per side, or until the internal temperature reaches 165°F (75°C).

Remove from the grill and let rest for a few minutes before slicing.

In each bowl, layer the roasted sweet potatoes, sliced grilled chicken, corn, black beans, cherry tomatoes, and avocado.

Drizzle with lime juice and sprinkle with chopped cilantro before serving.