Creamy potato croquettes with a crunchy golden coating are a Neapolitan and Sicilian street food staple. This vegetarian mediterranean snack is family-friendly and easy to prepare for freezer storage.
Place unpeeled potatoes in a large pot and cover with cold water; add 0.5 tsp salt. Bring to a boil over medium-high heat, then reduce to a simmer and cook for 18–22 minutes until tender through.
Drain potatoes, peel while still warm, and mash thoroughly until very smooth. Let cool just until no longer steaming hot to avoid scrambling the egg.
Stir in eggs, Parmesan, chopped parsley, nutmeg, remaining 0.75 tsp salt, black pepper, and mozzarella (if using). Mix until fully combined into a creamy, cohesive dough.
With oiled hands, shape mixture into logs about 3 inches long and 1 inch thick. Roll each croquette in breadcrumbs, ensuring an even, complete coating without gaps.
Heat 2 cups of vegetable oil in a deep skillet over medium-high heat (350°F). Fry crocchè in batches for 3–4 minutes, turning gently, until uniformly golden and crisp. Drain on paper towels and serve hot.