Preheat the oven to 425 degrees Fahrenheit.In a 10-inch (or slightly larger) oven-safe skillet or cast iron skillet, heat olive oil over medium heat. Add the chopped sweet potatoes, red pepper, jalapeno (if using) and onion. Once ingredients are sizzling, cover skillet* and continue (while stirring occasionally) to cook for about 10 minutes and until sweet potatoes are tender.Meanwhile, in a large bowl, whisk together eggs, milk, cilantro, salt and pepper.Uncover skillet, add seasonings and black beans, stir to combine.Pour egg mixture into skillet. Transfer skillet to oven and bake until egg mixture is set, about 20 minutes. Shake skillet slightly for a visual, to make sure egg is set. Serve with optional garnishes and/or a light side salad or a piece of toast.