Steak Recipe

Prep

Pat the thin beef filet slices dry with paper towels. Trim any excess fat. Slice the onion into thin half-moons, core and slice the green pepper into thin strips, and slice mushrooms into 1/4-inch slices. Mince the garlic.

Season meat

Place the beef slices in a bowl and season with 1 tsp kosher salt, 1/2 tsp black pepper, and the dried oregano. Toss to coat evenly and let rest 5–10 minutes at room temperature.

Cook vegetables

Heat 1 tablespoon oil and the butter in a large skillet over medium-high heat until shimmering. Add the onions and green peppers and a pinch (about 1/4 tsp) of salt. Cook, stirring occasionally, until softened and lightly browned, about 6–8 minutes. Push vegetables to the side of the pan.

Cook mushrooms and garlic

Add the remaining 1 tablespoon oil to the empty side of the pan. Add the mushrooms in a single layer and let them brown without moving for 2 minutes, then stir. Add the minced garlic and cook 30–45 seconds until fragrant. Combine mushrooms and garlic with the onions and peppers. Remove the vegetable mix to a bowl and keep warm.

Sear steak

Increase heat to high. Add the seasoned beef slices in a single layer (work in batches if necessary to avoid crowding). Sear undisturbed for 45–60 seconds, flip and cook another 30–45 seconds for just cooked-through thin slices (adjust time if your slices are thicker). Sprinkle remaining 1/2 tsp kosher salt and 1/2 tsp black pepper while searing if desired. Do not overcook—thin slices finish quickly.

Combine

Return the cooked vegetables to the pan with the seared steak. Toss quickly to combine and heat through, about 1 minute. Taste and adjust seasoning with additional salt and pepper if needed. Remove from heat.

Sprinkle the shredded mozzarella evenly over the steak and vegetable mixture in the pan. Cover the pan with a lid for 1–2 minutes or place briefly under a broiler (if using an oven-safe pan) until the cheese is melted and bubbly.

If using, drizzle the lemon juice over the finished mixture and sprinkle chopped parsley for brightness.

Serve the steak hot on toasted rolls for sandwiches or spoon over rice, mashed potatoes, or alongside a salad. Recipe yields roughly 4 lunch servings.