Preheat oven to 350°C/180°F.
On a work surface, use your hands to rub sweet potatoes with 10 ml of oil. Prick sweet potatoes with a fork. Place sweet potatoes on a baking sheet lined with parchment paper and bake on middle rack for about 25 minutes or until tender.
In the meantime, sauté sausage and peppers in the remaining oil for 4 minutes in a skillet over medium heat, stirring occasionally. Then add garlic, stir, and cook for 1 minute.
Once sweet potatoes are cooked, open and scoop out ⅓ of sweet potato flesh (reserve for another recipe).
Top sweet potatoes with sour cream, peppers and sausage mixture, chopped red onion, cherry tomatoes, Hojiblanca olives, and parsley.
Buen provecho!