Remove the top sirloin from the refrigerator 30 minutes before cooking to come to near room temperature. Pat the steak dry with paper towels to remove moisture—this promotes a better sear.

Make the marinade

In a small bowl, mince the garlic and combine with olive oil, soy sauce, Worcestershire sauce, black pepper, kosher salt, and thyme. Stir to combine.

Marinate

Brush or rub the marinade evenly over both sides of the steak. Let rest 15–30 minutes at room temperature (or up to 2 hours refrigerated) to absorb flavor. If refrigerating, bring back to room temperature for 30 minutes before cooking.

Preheat pan or grill

Place a heavy skillet (cast iron preferred) over medium-high heat and let it heat 5 minutes until very hot, or preheat a gas or charcoal grill to high. Add a thin film of oil to the pan and let it shimmer.

Sear the steak

Season the steak lightly again with a pinch of salt and pepper just before cooking. For a 1-inch top sirloin, sear 3–4 minutes per side for medium-rare (internal temp 125–130°F / 52–54°C), 4–5 minutes per side for medium (135°F / 57°C). Press gently with tongs to ensure contact with the pan; avoid flipping more than once.

Finish to temperature

If the steak thickens past 1" or needs longer to reach desired doneness, reduce heat to medium and continue cooking in the pan or move to indirect heat on the grill. Use an instant-read thermometer in the thickest part: 120–125°F rare, 125–130°F medium-rare, 130–140°F medium.

Rest the steak

Transfer steak to a cutting board and tent loosely with foil. Rest 7–10 minutes (depending on thickness) to allow juices to redistribute.

Slice and serve

Slice the steak across the grain into 1/4"–1/2" slices. Arrange on a platter and sprinkle with the chopped fresh thyme or parsley if desired.

Pan Sauce (optional)

Sauté shallot

While the steak rests, reduce heat to medium and add 1 tablespoon butter to the hot skillet. Add finely chopped shallot and cook 1–2 minutes until softened and translucent, scraping up browned bits from the pan.

Deglaze

Add red wine (or 1 tablespoon additional beef broth) to deglaze the pan, scraping the fond with a wooden spoon. Let the liquid reduce by half, about 1–2 minutes.

Make the sauce

Pour in 1 cup beef broth and bring to a simmer. Stir in Dijon mustard and simmer 3–4 minutes until slightly reduced and slightly thickened. Taste and adjust seasoning with salt and pepper as needed.

Finish with butter and herbs

Swirl in the remaining tablespoon of butter until glossy, then stir in chopped parsley. Spoon the sauce over sliced steak and serve immediately.