Using a fork, pierce the skins of the sweet potatoes in several places. Place an oven-proof rack on a cookie sheet and place the sweet potatoes on the rack. Bake at 400 degrees for 60-75 minutes or until the sweet potatoes feel soft when gently squeezed.
While the sweet potatoes are baking, prepare the black bean chili. In a medium saucepan, saute the onion in the olive oil for 3 minutes to soften. Add the green pepper and saute an additional 3-4 minutes or until the vegetables are tender. Add the tomatoes, garlic, and seasonings, and saute an additional 2 minutes. Add the black beans, tomato sauce, and season to taste with hot pepper sauce, stir well to combine, and simmer the chili for 10 minutes. Taste and adjust seasonings, to preference. Remove the saucepan from the heat.
When the sweet potatoes are tender, remove the cookie sheet from the oven and leave the sweet potatoes on the rack to cool for 5 minutes. For each serving, place one sweet potato on a plate or in a bowl, split it open, ladle some of the black bean chili over the top, and serve.