In a large bowl, combine ground beef, beaten egg, breadcrumbs, onion, garlic, Worcestershire sauce, Dijon mustard, and dried herbs with salt and pepper.

Using clean hands, gently mix until just combined—avoid overworking to keep the texture tender.

Chill the mixture for 15 minutes to make forming easier and ensure juicy steaks.

Divide into 4–6 portions and shape into oval patties about ¾ inch thick with a slight center indentation to prevent puffing.

Heat a cast-iron skillet over medium-high heat with a drizzle of oil or butter until hot but not smoking.

Cook patties for 4–5 minutes per side until a deep golden crust forms and the interior reaches 160°F (71°C) for medium doneness.

Avoid pressing down on them while searing—this preserves their natural juices.

Transfer cooked patties to a warm plate. In the same skillet, melt butter and cook sliced onions for 10–12 minutes until golden and caramelized.

Sprinkle in flour, cook for 1–2 minutes, then slowly whisk in beef broth, scraping up the flavorful browned bits.

Add a splash of Worcestershire sauce and let simmer until thickened.

Return patties to the pan, coat with gravy, and simmer for 2–3 minutes to meld flavors.

Plate each steak over a light pool of gravy and garnish with fresh parsley or thyme.