Chop 1 yellow onion.
Trim any excess fat off pork shoulder if needed.
In a small container, combine: 1tsp salt + 1/2tsp pepper + 1T Italian seasoning + 1 tsp garlic powder.
Heat 2T olive oil over med-high heat in a large sauté pan or heat sauté function in slow cooker.
Brown pork on all sides, ~3-4 mins per side. Place pork in slow cooker w/ chopped onion around the sides.
Cook pork ~7 hours. Remove some of the oil from slow cooker leaving ~2T.
Add 32 oz marinara sauce and cook an additional hour.
Cook pasta according to package directions.
Shred pork in marinara and serve over pasta w/ grated parmesan, if using.