Add the ground beef to a large mixing bowl.
Add bread crumbs, diced onion, egg, Worcestershire sauce, ketchup, Dijon mustard, minced garlic, onion powder, kosher salt, and cracked black pepper. Mix with either a large spoon or use your hands to mix the ingredients until thoroughly combined.
Measure out 1½ tablespoon scoops of the meat mixture. Form into round balls.
Add the extra virgin olive oil to a 12-inch nonstick skillet over medium-high heat. If you use a 10-inch skillet, you will need to cook the meatballs in batches.
Once the skillet is heated, add the meatballs to the skillet. Cook for 3 to 5 minutes per side, and turn to ensure even browning. Once the meatballs are completely cooked, remove them from the heat and prepare the gravy according to the package directions.
Once the gravy has been made, stir in the drained mushrooms. Serve the meatballs and mushroom gravy with mashed potatoes or egg noodles.