In a mixing bowl, combine ground beef, bread crumbs, finely chopped onion, egg, Worcestershire sauce, along with salt and pepper. Mix gently until just combined.

Shape the mixture into meatballs about 1.5 inches in diameter, yielding approximately 12 meatballs. Set aside.

Heat a large skillet over medium-high heat. Add oil, and brown the meatballs for about 4-5 minutes per side, then remove from skillet.

In the same skillet, add beef broth, ketchup, soy sauce, and cornstarch mixed with water. Bring to a simmer over medium heat for 3-4 minutes.

Return meatballs to skillet, immersing in gravy. Simmer for 5-7 minutes to heat through.

In a large pot of salted boiling water, cook peeled and cubed potatoes for 15-20 minutes until tender. Drain.

To the potatoes, add milk, butter, minced garlic, and chopped herbs. Mash until smooth, seasoning with salt and pepper.

Serve mashed potatoes on plates, topped with Salisbury steak meatballs and gravy.