Preheat the oven to 425°F.
Peel (if desired) and dice the small sweet potato into small cubes. Toss with a pinch of salt, pepper, and a drizzle of olive oil if preferred.
Spread the sweet potato cubes on a baking sheet and roast in the preheated oven for about 20-25 minutes until they are crispy on the edges, stirring halfway through.
While the sweet potato is roasting, whisk together the egg whites and whole egg in a bowl. Season lightly with salt and pepper.
Pour the egg mixture into a lightly non-stick skillet over medium heat and scramble until just set, ensuring a soft and fluffy texture.
Warm the 6-inch whole wheat tortilla in a dry skillet or microwave for a few seconds until pliable.
Heat the black beans if desired, either in a small pot or in the microwave.
Assemble the burrito by layering the roasted sweet potatoes, scrambled eggs, black beans, and fresh avocado (sliced or mashed) in the center of the tortilla.
Fold the sides of the tortilla over the filling, then roll tightly to form the burrito.
Serve immediately and enjoy this balanced, flavorful meal.