Preheat the oven to 230°C (450°F) and cover a baking sheet with parchment paper.
Cut the sweet potatoes in half, lengthwise. Moist them with a olive oil drizzzle and season with salt and pepper. Place them on the baking sheet, inner side down (and therefore peel side up). Bake for 30 minutes.
During this meantime, cut the other vegetables: the bell pepper into strips, the tomato into small cubes, chop the garlic and mince the chives (keep the green part for serving). If your corn is frozen, heat it up in the microwave oven.
In a frying pan, heat an olive oil drizzle. Add the chives white parts and the garlic. Saute for 1 minute and then, add the bell pepper strips. Saute for about 10 minutes, then add the corn, the beans, the tomato, the chili powder and 1 cup of water (to avoid sticking to the pan). Saute for more 5 minutes.
Once the sweet potatoes are cooked, remove the inner center of them with a spoon (leave some peel around the edges). Coarsely mash this obtained potato and add it to the previous mixture.
Fill the sweet potatoes with the mixture. Sprinkle with the chives green parts and coriander (or parsley), and a few drops of tabasco for a some extra spice. Serve with tortillas and guacamole.