Mix salt, pepper, oregano, cumin, and olive oil in a small bowl. Rub all over pork and then place into slow cooker.

Slice onion, mince garlic, and juice 2 oranges;add to slow cooker on top of pork. Cover and cook on low for 8-10 hours (or on high for 6 hours).

For the quinoa salad: heat the oil in a large saucepan over medium. Mince ginger and garlic, slice green onion, and roughly chop spinach. Add ginger, garlic, and onions to the hot pan and sauté for 2 minutes. Add raw quinoa, broth, and soy sauce; stir to combine. Bring to a boil, reduce heat, cover, and cook for 20 minutes or until all the liquid has been absorbed. Remove from heat and stir in spinach.

Serve pork with quinoa and remaining orange wedges on the side.