Preheat oven to 220 degrees. Wrap each sweet potato in foil and cook for an hour until they get soft.
Meanwhile, pour the oil into the pan, add the chopped onion, the garlic, and the salt. Simmer on low heat for 10 minutes.
Add the beans with all the liquid, herbs, paprika powder, a little chili and fry them. Cover them and simmer for 10 minutes while the mixture is still juicy but no longer liquid. The sauce should be sticky rather than liquid.
When the potatoes are done, cut them in the middle from the top and only to the middle. Fill with beans, pour yogurt, add a little more chili, pepper and serve alone or with a salad.