Add olive oil to a Dutch oven set over medium heat. Add in the onion and cook until tender, about 3 minutes. Then add in the garlic, pork, and beef. Cook, stirring frequently, until the pork and beef are browned. Add the sweet potato, celery, crushed tomatoes, Worcestershire sauce, cumin and chili powder. Stir to combine, cover and allow to simmer until the sweet potatoes are fork tender, about 30 minutes. Serve with toppings.