Toothpicks, metal skewers or wooden skewers soaked in water for 30 minutes
Remove the heads of the sardines and pull out the backbones and entrails. Rinse each sardine in cold water and pat dry with a paper towel. Set aside to soak for about 1 hour in a shallow dish filled with the white wine vinegar. In a 2-quart saucepan, heat the olive oil over medium heat. When the oil begins to shimmer, add 2 cloves sliced garlic and 3 sardines and cook until they disintegrate. Using a wooden spoon, stir in the breadcrumbs until they are well-moistened. Add the Caviocavallo, raisins, parsley and pine nuts. Season, to taste, with salt and pepper. Continue stirring over medium heat for about 2 minutes.
Remove the stuffing from the heat. Lay 1 orange slice in each sardine, then spoon 1 tablespoon of the bread crumb stuffing. Using toothpicks, close fish securely.
Using a fork, beat the eggs in a shallow bowl. Spread some flour in a baking dish. Carefully, so as not to damage the sardines, gently dredge each sardine first through the egg mixture and then through the flour, shaking gently at the end to remove the
excess flour. Saute in pan with oil until golden brown.
Transfers to plates and garnish with fennel fronds, sea salt, cracked pepperocini, orange juice, extra-virgin olive oil, black pepper and mint leaves.