In a large bowl, combine ground beef, breadcrumbs, ketchup egg, garlic, salt, and pepper. Shape mixture into 4 oval steaks and place on a plate.
Heat vegetable oil in a large skillet over medium high heat. Add steaks and sear on both sides 3-5 minutes until golden brown. Transfer to a plate and set aside.
Heat same pan with the drippings over medium-high heat. Add onion and saute several minutes until tender. Add mushrooms and cook an additional few minutes until tender. Add flour and cook an additional minute.
Reduce heat to medium and slowly begin drizzling in beef broth, stirring constantly until sauce is smooth. Add Worcestershire and Dijon and bring sauce to a simmer.
Nestle steaks back into pan and reduce heat to medium-low. Cover pan and cook steaks in sauce 10-12 minutes until steaks register 165F, flipping steaks and basting with sauce occasionally.
Season sauce with salt and pepper to taste if needed. Top steaks with parsley and serve warm with gravy over mashed potatoes. Enjoy!