In a large bowl, stir turkey, egg, breadcrumbs, half the diced onion, ketchup and spices together until combined. Form 6-7 patties and brown both sides in 1 tablespoon olive oil in large, deep skillet. Remove from pan and set aside. Patties will not be cooked completely and that's totally ok!: The bowl will fill with the soft scent of ground turkey and the faint sweetness from ketchup as you fold ingredients together. Use your hands or a spoon to fold gently until the mixture feels cohesive, but stop once it holds shape to avoid compressing the meat into a dense texture. You'll notice the mix slightly tacky from the egg and breadcrumbs , which is what helps form tender patties. A common mistake here is over mixing; that squeezes out moisture and yields tough steaks. To check readiness, press a small portion between fingers if it springs back gently, you are good. Working in a cool environment also helps maintain moisture, especially with lean ground turkey .
Pour in remaining 1 tablespoon of olive oil into skillet. Saute last of the onions and mushrooms until browned and tender, about 5 minutes. Remove from pan and set aside.: As the patties hit the hot oil, you should hear an immediate sizzle and smell a toasty aroma that signals the Maillard reaction starting. Browning both sides builds color and deep flavor, giving you that appealing crust. Keep the skillet hot but not smoking, and resist moving the patties prematurely so the crust can set. If you try to flip too early the surface will stick and tear. Watch for a golden brown color, approximately a few minutes per side depending on thickness. Remember these will not be fully cooked yet, so focus on deep sear rather than doneness.
Melt tablespoon of butter into pan. Sprinkle in flour and whisk to form a paste. It might seem to form crumbs because it's a little dry; that's ok! Slowly whisk in beef broth to avoid lumps. Bring to boil to thicken, then reduce heat to simmer. Pour in Worcestershire sauce. Slide in browned turkey steaks and spoon sauce over to coat. Add in cooked mushrooms and onions overtop and cover. Simmer 10 minutes or until gravy thickens even more and turkey steaks and cooked thoroughly.: When the patties leave the skillet, the pan will be studded with browned bits, which are flavor gold for your gravy. Let the patties rest briefly on a plate while you reuse that fond. If you stack them, be cautious as residual heat continues to cook the centers. A common oversight is discarding the fond; scraping and deglazing it later is essential for a rich sauce. Keep the reserved patties within easy reach so you can return them to the pan to finish cooking in the gravy.
Serve over mashed potatoes, if desired.: Adding the second tablespoon of olive oil revitalizes the pan and prevents the vegetables from sticking, while also capturing flavors from the fond. Heat it until it shimmers but does not smoke, then move quickly to add vegetables so they begin to brown instead of steam. Overheating the oil can scorch the onions, creating bitterness that will carry into the sauce; keep the temperature medium high for controlled caramelization.
Saute last of the onions and mushrooms until browned and tender, about 5 minutes: As the onion hits the pan you will smell its sweetness begin to unfold, and when the mushrooms release their juices you will see them reduce and concentrate into brown bits. Stir enough to promote even cooking, and watch for deep color and soft but not falling apart texture. If the pan becomes crowded, the vegetables will steam and not brown, so give them breathing room. Once they are nicely browned, remove and set aside to keep their texture distinct before adding them back into the sauce.
Melt tablespoon of butter into pan: Melting the butter creates a glossy base for the roux and adds a silky mouthfeel to the finished gravy. Keep the heat moderate to avoid browning the butter too quickly; you want it just melted and foamy. If the butter browns, it can add a nutty note which may be pleasant, but be mindful not to let it burn as that introduces unwanted bitterness.
Sprinkle in flour and whisk to form a paste: When you add the flour , it will combine with the melted butter into a paste that looks grainy at first. Whisk vigorously so the flour cooks slightly and loses any raw chalky taste. A dry appearing paste is normal; the next step of slowly adding beef broth transforms it into a smooth sauce. Not whisking properly is a frequent source of lumps, so keep the whisk moving and incorporate the liquid gradually.
Slowly whisk in beef broth to avoid lumps: As you pour in the beef broth in a thin stream while whisking, the paste will loosen and turn silky. This is when the aroma shifts into rich, savory territory. Go slowly to maintain a smooth texture, and scrape up the fond from the pan to deepen the sauce. If lumps form, reduce heat and whisk vigorously until they disperse. Avoid dumping the liquid all at once, which invites clumps and an uneven gravy.
Bring to boil to thicken, then reduce heat to simmer: Bringing the sauce briefly to a boil activates the thickening power of the roux, and you will see the gravy coat the back of a spoon when it is ready. Once thickened, reduce to a gentle simmer to prevent over reduction and to meld flavors. Simmering also moderates the intensity and lets the sauce finish cooking without scorching. A rapid boil for too long will over concentrate and can turn the sauce pasty.
Pour in Worcestershire sauce: Adding a dash of Worcestershire injects umami and a subtle tang that balances the richness of the gravy. Stir it in and taste, adjusting salt and pepper if necessary. Because it is concentrated, add sparingly and incrementally to avoid overpowering the sauce. If you add too much, a bit more broth can help tame the intensity.
Slide in browned turkey steaks and spoon sauce over to coat: Nestle the reserved patties into the sauce so each one is partially submerged and the gravy can gently finish the cooking. Spooning sauce over them repeatedly ensures even heat and flavor penetration. You should hear a soft simmer around the edges, and the tops will glisten as they absorb the gravy. Avoid crowding the pan which might cool the sauce and prevent gentle simmering.
Add in cooked mushrooms and onions overtop and cover: Return the browned mushrooms and remaining onion on top of the patties, which concentrates their aroma over the meat while they steam under the cover. The cover traps steam and promotes even internal cooking without drying the patties. If you leave the pan uncovered you risk reducing the sauce too quickly and drying out the steaks.
Simmer 10 minutes or until gravy thickens even more and turkey steaks and cooked thoroughly: During this simmer the gravy should thicken further and the internal temperature of the patties will rise until fully cooked. You will see small bubbles and a glossy surface; the patties will feel springy yet firm when gently pressed. Over simmering can make the patties dry, so check for doneness around the 10 minute mark and remove once juices run clear and the gravy reaches your desired thickness.
Serve over mashed potatoes, if desired: The final presentation is satisfying, with the glossy gravy cascading over mounded mashed potatoes or rice. The aroma will be rich and savory, and textures will contrast nicely between fluffy starch and tender patties. Serve immediately for best texture, as the sauce will thicken as it cools. Reheating gently with a splash of broth restores the gravy vibrancy if needed.