In a bowl, add the ground beef, ground pork, garlic powder, onion powder, dried oregano, sea salt, and black pepper.
Combine by hand until thoroughly mixed.
Divide the mixture into 4 roughly equal sized portions.
Shape individual burger patties by hand.
Cover on a plate and place into the fridge for at least 30 minutes.
Heat a griddle pan over medium-high heat.
Brush 4 pineapple slices with 1 tablespoon olive oil.
Place the slices into the pan and cook for 2 minutes on each side, until lightly charred.
Remove pineapple from the pan and set aside.
To cook the burgers, heat a clean, heavy bottomed pan with 1 tablespoon oil over medium-high heat.
Add the patties to the pan, making sure not to overcrowd the pan (you may need to cook patties in batches). Cook for 4 minutes on one side before flipping.
Cook for another 4 minutes on the other side, until browned and cooked through.
Top each patty with a slice of mozzarella.
Remove from the pan and set aside.
To assemble the burgers, spread the base of a burger bun with barbecue sauce.
Layer on the arugula and then the hot burger patty.
Top with the pineapple rings and sliced red onion.
Spread chili jam on the top burger bun and place on top. Serve immediately.