3 pounds yellow potatoes (or about 6 medium potatoes)
1/2 cup onion (finely chopped)
2 cloves garlic (minced)
1 tablespoon aji pepper (minced; or aji pepper paste, or minced jalapeño to taste)
Vegetable oil (for cooking)
1 teaspoon cumin
1/2 teaspoon paprika
3/4 pound ground beef
3/4 cup beef broth
1/3 cup raisins
Optional: 1/3 cup green olives (chopped)
1/2 teaspoon salt (or to taste)
1/4 teaspoon pepper (or to taste)
1/2 cup flour (for dusting; or more as needed)
Cook one of the eggs in boiling water until hard-boiled and set aside. Reserve the other egg. Bring a large pot of salted water to a boil. Cook the unpeeled potatoes until they are tender when pierced with a fork. While the potatoes are cooking, cook the onions, garlic, and aji pepper in the vegetable oil until soft and fragrant. Add the cumin and paprika to the onions and cook 2 minutes more, stirring. Add the ground beef and cook until browned. Add the beef broth and the raisins and simmer for 10 to 15 minutes more, or until most of the liquid is gone. Stir in the green olives, if using. Season mixture with salt and pepper to taste. Remove from heat and let cool. When the potatoes are cooked, drain them in a colander. When they are cool enough to handle, peel them, and then mash the potatoes thoroughly (or pass them through a potato ricer). Season the mashed potatoes with salt and pepper to taste. Chill the potatoes uncovered for several hours, or overnight. Once the potatoes are very cold, stir the reserved egg into the mashed potatoes until well mixed. Peel the hard-boiled egg and chop into about six pieces. With floured hands, place about 1/4 cup of mashed potatoes in one hand, and make a well in the center. Fill the well with 1 to 2 tablespoons of the beef mixture and a piece of hard-boiled egg. Mold the potatoes around the beef, adding more potatoes if necessary to fully enclose the filling, and shape the whole thing into an oblong potato shape, with slightly pointy ends, about the size of a medium potato. Repeat with the rest of the mashed potatoes. Coat each stuffed "potato" generously with flour. In a deep skillet or deep-fat fryer, heat 2 inches of oil to 360 F. Fry the potatoes in batches until they are golden brown. Drain them on a plate lined with paper towels. Keep the potatoes warm in a 200 F oven until ready to serve.