Gather a large bowl and combine the ground beef, eggs, bread crumbs, 1/4 cup of parsley, 3 cloves of garlic, a pinch of salt, and a sprinkle of pepper. Mix everything together until well combined. Then, take portions of the ground beef mixture and shape them into balls about the size of a golf ball.
Prepare a cast iron pan or skillet by heating it over medium-high heat with a drizzle of oil. Once the pan is hot, carefully add the meatballs and cook them until they turn a golden brown colour on all sides. Once cooked, transfer the meatballs to a plate and set the pan aside.
Preheat your oven to 350 degrees F (180 degrees C). Take some soft rolls and place them on a baking sheet. Using a knife, cut off the top of each roll and press down the inside to create a hollow space resembling a boat.
In a separate bowl, melt some butter and mix it with 3 cloves of minced garlic and 2 tablespoons of chopped parsley. Brush this garlic butter mixture onto the rolls, coating them evenly. Then, place the rolls in the oven and bake them for about 5 minutes or until they become nicely toasted.
Once the rolls are ready, take them out of the oven and layer two slices of mozzarella cheese inside each roll. Spoon a dollop of marinara sauce on top of the cheese. Now, carefully place three meatballs inside each roll, arranging them neatly. Finally, add some more marinara sauce on top of the meatballs.
Return the rolls to the oven and bake them for approximately 25 minutes, or until the cheese is completely melted and gooey. Once done, remove the rolls from the oven and sprinkle them with grated Parmesan cheese for an extra burst of flavour.
And voila! Your delicious meatball boats are now ready to be enjoyed. Serve them warm and savour every bite of this delectable culinary creation.