Preheat oven to 400°Line a baking sheet with parchment paper; set aside.

Using a medium bowl, combine the bread crumbs and milk; let soak for 5 minutes.

Meanwhile, add the olive oil to a medium frying pan and place over medium-high heat. Once hot, add the diced onions and cook for 6-7 minutes, or until onions begin to soften.

Transfer onions and soaked bread crumbs into a large mixing bowl. Add all of the remaining meatball ingredients (beef, pork, egg, parsley, garlic, salt, pepper, oregano, red pepper and Parmesan cheese). Mix until just combined. (Tip: Take care not to overmix or the meatball may be tough.)

Using a medium mixing bowl, whisk together sauce ingredients (barbecue sauce, Worcestershire sauce, honey and smoked paprika). Transfer mixture into a slow cooker.

Add cooked meatballs and stir gently until meatballs are well-coated.

Cook on low for 3-4 hours.

Set oven to low broil.

Open sub rolls and lay flat on a parchment-lined sheet pan. Using a slotted spoon, place 4-5 meatballs onto each sub roll. Add a spoonful or two of sauce on top of meatballs.

Broil subs for 3-5 minutes, or until rolls are lightly toasted.