Step 1: Prepare the Panade and Meatball Mixture

1. Make the Panade: In a small bowl, combine the fresh breadcrumbs (or Panko) and milk. Let it sit for 5-10 minutes to allow the breadcrumbs to absorb the liquid fully. This is crucial for tender meatballs.
2. Combine Wet Ingredients: In a large mixing bowl, lightly beat the egg. Add the grated Parmesan cheese, chopped parsley, minced garlic, salt, black pepper, dried oregano, and optional red pepper flakes. Mix well.
3. Add Meats and Panade: Add the ground beef, ground pork, and the soaked breadcrumb mixture (panade) to the bowl with the egg mixture.
4. Mix Gently: Using your hands, gently combine all the ingredients until just incorporated. Be careful not to overmix! Overmixing develops the gluten in the meat and can lead to tough meatballs. The mixture should be uniform but still light.

Step 2: Form and Cook the Meatballs

1. Form Meatballs: Lightly wet your hands to prevent sticking. Gently roll the mixture into meatballs, about 1.5 to 2 inches in diameter (you should get about 20-24). Place them on a baking sheet lined with parchment paper.
2. Sear the Meatballs (Optional but Recommended for Flavor): Heat 2 tablespoons of olive oil in a large, heavy-bottomed skillet or Dutch oven over medium-high heat. Working in batches to avoid overcrowding the pan, sear the meatballs on all sides until nicely browned. This develops a delicious crust. They don’t need to be cooked through at this stage. Remove seared meatballs and set aside.

   • Alternatively, for an easier, less messy option: You can bake the meatballs. Preheat oven to 400°F (200°C). Place meatballs on a parchment-lined baking sheet and bake for 15-20 minutes, or until browned and mostly cooked through.

Step 3: Make the Marinara Sauce (While Meatballs Rest/Bake)

1. Sauté Aromatics: If you seared your meatballs in a Dutch oven, you can use the same pot (drain excess fat if necessary, leaving about 1 tablespoon of drippings for flavor). Otherwise, heat 1 tablespoon of olive oil in a large saucepan or Dutch oven over medium heat. Add the chopped onion and cook until softened and translucent, about 5-7 minutes.
2. Add Garlic: Add the minced garlic and cook for another minute until fragrant, being careful not to burn it.
3. Build the Sauce: Stir in the crushed tomatoes, tomato sauce, dried oregano, dried basil (if using dried), salt, pepper, optional sugar, and optional red pepper flakes. Bring the sauce to a simmer.
4. Simmer with Meatballs: Gently add the seared (or baked) meatballs to the simmering sauce. Ensure they are mostly submerged. Reduce the heat to low, cover, and let the meatballs simmer in the sauce for at least 30 minutes, or up to 1-2 hours for maximum flavor melding. The longer they simmer, the more tender they become and the richer the sauce. Stir occasionally to prevent sticking. If using fresh basil, stir it in during the last 5 minutes of simmering.

Step 4: Assemble and Bake the Meatball Subs

1. Preheat Oven: Preheat your oven to 375°F (190°C). If you want an extra crispy top, you can also use the broiler for the last minute or two, so position an oven rack accordingly.
2. Prepare the Rolls: Slice the hoagie rolls lengthwise, but not all the way through, creating a hinge. Gently hollow out some of the soft bread from the inside of both halves if desired – this creates more room for meatballs and helps prevent them from rolling out.
3. Optional – Toast Bread with Garlic Butter: Mix melted butter with minced garlic. Lightly brush the inside of the rolls with the garlic butter. Place them cut-side up on a baking sheet and toast in the preheated oven for 3-5 minutes, or until lightly golden and fragrant. This step adds incredible flavor and helps prevent the bread from getting soggy.
4. Load the Subs: Remove the rolls from the oven. Spoon a little marinara sauce onto the bottom half of each roll. Arrange 3-4 meatballs (depending on their size and the roll’s length) snugly into each roll.
5. Sauce and Cheese: Spoon a generous amount of extra marinara sauce over the meatballs. Top lavishly with slices of provolone or mozzarella cheese, ensuring the meatballs are well covered.
6. Bake/Broil: Place the assembled subs back on the baking sheet. Bake for 8-12 minutes, or until the cheese is melted, bubbly, and slightly golden, and the subs are heated through. For an extra golden, bubbly cheese topping, you can switch to the broiler for the last 1-2 minutes, watching very carefully to prevent burning.
7. Rest and Serve: Let the meatball subs rest for a few minutes before serving. This allows the cheese to set slightly and prevents a molten lava situation. Garnish with fresh basil or parsley and a sprinkle of extra Parmesan cheese, if desired.