Sprinkle both sides of pork with pepper. In large skillet over medium-high heat, heat 1 tablespoon canola oil. Cook pork chops for 4 minutes on each side, or until internal temperature reaches 160 degrees.
Reserve 4 pork chops in refrigerator to make Pressed Pepperoncini-Pork Sandwiches (recipe below).
In skillet over medium-high heat, heat remaining canola oil; tilt skillet to coat bottom lightly. Cook mushrooms 4-5 minutes, or until tender and juices begin to release, stirring occasionally.
Stir in garlic and 1/4 teaspoon salt; cook for 15 seconds, stirring constantly. Place over pork chops and cover to keep warm.
To pan residue, add vinegar, water, Worcestershire sauce, sugar and remaining salt. Bring to boil over medium-high heat and boil 1-1/2 to 2 minutes, or until reduced to 2 tablespoons, scraping bottom and sides of skillet.
Drizzle sauce over pork and mushrooms. Sprinkle with onions.