Preheat the oven to 350ºF. While the oven preheats, boil some water.
Place the raisins in a small bowl and cover them with boiling water. Let them plump in the water for 10 minutes.
Sauté the chopped onion, garlic, and peppers in the olive oil until soft and fragrant.
Add the cumin and paprika and cook 2 minutes more, stirring. Add the ground beef and cook until browned.
Drain the raisins and add them to the ground beef. Add the beef broth and simmer for 10 to 15 minutes more, or until most of the liquid is gone.
Stir in the hard-boiled egg and the black olives. Season mixture with salt and pepper to taste.
Remove beef mixture from heat and let cool for 5 minutes. Stir in 1/2 cup crumbled queso fresco.
While the beef is cooking, bring a large pot of salted water to a rolling boil. Slice the tops off of the peppers and reserve. Clean the inside of the peppers, removing the seeds and veins.
Cook the peppers in the boiling water until bright red and just tender, about 8 to 10 minutes. Drain peppers and blot dry with paper towels.
Fill each pepper with some seasoned ground beef mixture. Top with remaining queso fresco.
Place the peppers on a baking sheet, with the tops alongside them (but not covering the filling). Bake the peppers for 10 to 15 minutes, or until the cheese is melted and the filling is heated through.