In a small bowl, whisk together the BBQ sauce and the blueberry preserves and set aside.

In a large bowl, combine the ground beef, ground pork, BBQ seasoning, parmesan cheese, diced onion, egg, milk and breadcrumbs. Mix using a wooden spoon or hands.

Roll the meatball mixture into 2.5oz balls and set aside.

Heat a nonstick skillet over medium heat and add the olive oil. Brown the meatballs on each side, about 1 minute per side. Do not cook all the way through.

Spray a 6 quart slow cooker with nonstick cooking spray. Add the meatballs and half of the BBQ sauce mixture. Cook on high for 2-3 hours or low 4-5 hours.

When done, remove the meatballs from the slow cooker using tongs and discard the leftover cooking liquid. Coat the meatballs with the rest of the BBQ sauce mixture and serve. Garnish with sliced green onion if desired.