Ingredients:

  • 1 lb (450 g) ground beef, 80/20
  • 1/2 cup (55 g) plain dry breadcrumbs
  • 1/4 cup (60 ml) whole milk
  • 1 large egg
  • 1/3 cup (30 g) finely grated Parmesan
  • 2 cloves garlic, minced
  • 2 tbsp (8 g) finely chopped fresh parsley
  • 1 tsp (1 g) dried oregano
  • 3/4 tsp (4 g) kosher salt
  • 1/2 tsp (1 g) ground black pepper
  • 1/4 tsp (0.5 g) red pepper flakes
  • 1 tbsp (15 ml) olive oil
  • 1/2 small yellow onion, finely diced (about 75 g)
  • 1 clove garlic, minced
  • 3 cups (720 ml) marinara sauce (about one 24 oz / 680 g jar)
  • 4 fresh basil leaves, torn
  • 6 sub or hoagie rolls (about 6 in / 15 cm each)
  • 2 tbsp (28 g) unsalted butter, melted
  • 8 oz (225 g) low-moisture mozzarella, shredded

Instructions:

  1. Preheat the oven to 400°F (200°C). Line a rimmed baking sheet with parchment paper.
  2. In a large bowl, stir the milk into the breadcrumbs. Let sit 5 minutes until the mixture looks like wet oatmeal.
  3. Stir the egg, Parmesan, minced garlic, parsley, oregano, kosher salt, black pepper, and red pepper flakes into the soaked breadcrumbs until uniform.
  4. Add the ground beef and mix gently with your hands for about 30 seconds, just until no dry streaks remain. Do not overwork the meat.
  5. Shape the mixture into about 18 balls, roughly 1 1/2 inches (4 cm) across, each about 25 g.
  6. Arrange the meatballs about 1 inch apart on the prepared sheet. Bake 18 to 20 minutes, until deep brown outside and an instant-read thermometer reads 160°F (71°C) inside.
  7. Meanwhile, heat the olive oil in a medium saucepan with a lid over medium heat. Cook the diced onion 4 to 5 minutes, until translucent. Add the 1 clove minced garlic and stir 30 seconds, until fragrant. Remove from heat if the garlic starts to brown.
  8. Pour in the marinara sauce, reduce heat to low, and simmer about 10 minutes, stirring occasionally, until it bubbles in slow, lazy blops.
  9. Add the baked meatballs to the sauce, cover, and simmer 5 minutes. Stir in the torn basil.
  10. Set the oven to broil on high. Slice each of the 6 sub or hoagie rolls open without cutting all the way through. Brush the cut sides with melted butter and lay them open on a baking sheet.
  11. Nestle 3 meatballs into each roll, ladle sauce over them, and top generously with the shredded mozzarella.
  12. Broil 1 to 2 minutes, watching closely, until the cheese bubbles and the bread edges turn golden. Remove right away.