In a large mixing bowl, combine the ground beef, ricotta cheese, breadcrumbs, Parmesan cheese, minced garlic, parsley, egg, salt, black pepper, and dried oregano. Mix everything together until well combined.
Shape the mixture into small meatballs, about 1-2 inches in diameter. You should be able to make approximately 20-25 meatballs.
Heat the olive oil in a large skillet over medium heat. Once the oil is hot, add the meatballs in batches, making sure not to overcrowd the pan. Cook the meatballs for about 6-8 minutes, turning them occasionally, until they are browned on all sides and cooked through. Transfer the cooked meatballs to a plate lined with paper towels to drain any excess oil.
Repeat the process with the remaining meatballs until they are all cooked.
Serve the Polpette alla Ricotta hot with marinara sauce on top. They can be served as an appetizer, with pasta, or as a main dish with a side of salad or vegetables.