Wagyu Beef Meatball Sandwich

To make marinara sauce, in a large wide pot over medium-low heat, heat oil. Add onions and garlic, and sauté 5-8 minutes, or until softened and translucent. Stir in salt, sugar, and cayenne; cook 2 minutes. Add tomatoes and bring to a simmer. Simmer gently, stirring occasionally, for 15 minutes. Whisk in butter and balsamic. Season with salt and pepper and keep warm.

Meanwhile, for the pesto, combine broccoli rabe, peppers, pickling liquid, garlic, red pepper flakes and Parmesan in a food processor. While machine is running, slowly stream in oil until blended. Season to taste with salt and pepper and set aside.

In a medium bowl, stir butter, parsley and garlic until blended. Season with salt and pepper, and set aside.

*Note: The sauce, pesto and garlic butter can be made up to 2 days ahead, stored separately, covered and refrigerated. Bring garlic butter to room temperature before spreading.

To make meatballs, in a large bowl, combine bread crumbs and buttermilk. Set aside 30 minutes to allow bread to absorb liquid. Squeeze out any excess buttermilk from bread. Using your hands, mash bread crumbs. Add ground beef, pork, parsley, Parmesan, 1/2 cup Pecorino, garlic, salt, oregano, red pepper flakes, fennel seeds and black pepper; mix until blended. Blend eggs in blender for 1 minute then add them to meat mixture. Using your hands, gently mix until blended. Mixture will be soft, which will ensure tender meatballs. Form mixture into 12 meatballs.

Heat a large, heavy skillet over medium heat. Add olive oil. Working in batches, add meatballs and cook, turning occasionally, for 12 minutes per batch, or until browned all over. Using a slotted spoon, transfer to a plate to drain.

When all the meatballs are cooked, add them to the marinara and simmer 5 minutes, or until meatballs are cooked through, with no sign of pink.

To assemble sandwiches, preheat oven broiler. Spread garlic butter over cut sides of hoagie rolls and broil 1 to 2 minutes, until toasted. Spread pesto over toasted rolls then spoon three meatballs onto the bottom of each roll and top with more sauce. Scatter mozzarella over meatballs and broil 1-2 minutes, or until cheese is melted. Sprinkle with more Pecorino cheese and serve immediately.