Marinate: Whisk whiskey, soy sauce, olive oil, garlic, Worcestershire, and pepper. Coat steaks and marinate 30 minutes at room temperature (or up to 4 hours refrigerated).
Make the glaze: Simmer all glaze ingredients except butter for 6–8 minutes until glossy and thickened. Whisk in butter off the heat. Set aside.
Dry & season: Pat steaks completely dry. Season both sides generously with kosher salt.
Sear: Heat oil in a cast-iron skillet over high heat until nearly smoking. Sear steaks 3–4 minutes per side for a deep crust.
Baste: Lower heat to medium, add butter and herbs, and spoon foaming butter over the steaks for about 1 minute.
Check temp: Pull at 130–135°F for medium-rare (5°F below target).
Glaze & rest: Brush with glaze in the final minute. Rest 5–10 minutes, finish with flaky salt, and serve with extra glaze.