Preheat your oven to 200C. Rub 1 tbsp of olive oil over your two sweet potatoes and roast them for 60 - 90 minutes. Slide a knife through the middle of the sweet potato to check for doneness (it should slide through easily).
Meanwhile, make the filling. Heat the remaining oil in a pan and add the diced onion and red pepper. Saute for 5-6 minutes until softened, and then add the minced garlic and cook for another minute.
Add the spices, drained black beans, and sweetcorn. Simmer everything for 4-5 minutes on low heat, stirring often.
Once the potatoes are cooked, cut them in half lengthwise, scoop out the sweet potato flesh, and add it to a bowl.
Mash the sweet potato and add the black bean mixture, sour cream, half of the cheese, and enchilada sauce (leave about 4 tbsp to top the potatoes with). Mix everything.
Spoon the mixture back into the sweet potato skins, topping with the remaining cheese.
Grill the potatoes for 4-5 minutes until the cheese is melted and golden.
Top with the guacamole and the remaining warmed enchilada sauce.
