Season both sides of pork chops with salt, pepper, garlic and oregano. Heat oil in a skillet on medium-high heat until hot. Sear pork chops in hot pan on each side for approximately 3 minutes on each side or until nicely browned. Remove pork chops from pan (we're not cooking them through, just searing them).
Add onions to hot pan, season with salt and pepper and sauté for 2 minutes. Reduce heat to medium then add flour to the onions. Stir to coat onions with flour and continue cooking for 2-3 more minutes, stirring occasionally.
Slowly add chicken broth and mushrooms (drained) to onions and stir until smooth and mixture begins to thicken. Taste for seasoning then add salt and pepper if necessary. Reduce heat to low, add pork chops back to pan then cover and cook for 30 minutes to an hour (you want to see a slight simmer – bump the heat up a notch if you need to). The longer you cook it, the more tender the pork chops will be (so long as you don’t let them boil – keep it at a simmer and you’ll be ok!).
Serve gravy over pork chops and rice, angel hair pasta, or mashed potatoes.