In a large bowl, combine beef, breadcrumbs, egg, and spices. Mix until just incorporated.
Form the mixture into 4 oval patties, approximately 3/4 inch thick.
Heat vegetable oil in a large skillet over medium-high heat.
Sear patties for 3-4 minutes per side until well-browned, then remove from skillet and set aside.
In the same skillet, add sliced onions and mushrooms; sauté for 8-10 minutes until softened and deeply browned.
Whisk the flour into the water to create a smooth slurry.
Pour beef broth and Worcestershire sauce into the skillet with the vegetables, scraping the bottom of the pan to release browned bits.
Stir in the flour slurry and bring to a simmer until the gravy thickens.
Return the hamburger steaks to the skillet, spooning the onion and mushroom gravy over them.
Cover and simmer on low heat for 10 minutes or until steaks reach an internal temperature of 160 degrees Fahrenheit.