Combine ground beef, breadcrumbs, minced garlic, chopped parsley, beaten egg, grated Parmesan, a pinch of salt and pepper in a large bowl. Mix gently with your hands until just combined, being careful not to overmix to keep the meatballs tender.
Shape the mixture into small, rustic balls about 1 inch in diameter, using your hands. Place them on a lined baking sheet or set aside for frying.
If frying, heat enough oil in a skillet to cover about 2-3 inches and heat until shimmering (~180°C / 350°F). If baking, preheat your oven to 200°C (390°F) and line a baking sheet with parchment paper.
Fry the meatballs in batches, turning every 2-3 minutes, until they are golden brown and cooked through, about 8-10 minutes. Alternatively, bake the meatballs for 20 minutes until they are crispy on the outside and firm inside.
Use a cooking thermometer to check that the internal temperature reaches 70°C (160°F), ensuring they are fully cooked. Drain on paper towels if fried to remove excess oil.
Serve the meatballs warm, with toothpicks or your favorite dipping sauce. These rustic bites are best enjoyed immediately, bursting with flavor and warmth.