Step 1: Prep the Tenderloin
Let the beef come to room temp 30–60 minutes before cooking.
Pat dry. Rub with olive oil.
Mix black pepper, salt, garlic powder, and rosemary. Coat the roast thoroughly.
Optional: tie with butcher’s twine for uniform shape.
Step 2: Sear
Heat a heavy oven-safe skillet (cast iron preferred) over medium-high heat.
Add butter and a little oil.
Sear tenderloin on all sides until deeply browned (6–8 minutes total).
Transfer skillet to a preheated 400°F oven.
Step 3: Roast
Roast until internal temp reaches:
120°F for rare
125–130°F for medium-rare
135°F for medium
(This usually takes 18–25 minutes, depending on size and oven.)
Remove from oven, transfer to cutting board, and tent loosely with foil. Rest 15 minutes.
Step 4: Make the Sauce
Return skillet to stove over medium heat.
Add 1 tbsp butter and shallots; sauté 2–3 minutes.
Deglaze with red wine, scraping up any fond.
Simmer 2 minutes, then add broth, mustard, and vinegar.
Reduce slightly, about 5–7 minutes.
Optional: whisk in 1 tbsp cold butter to finish. Season to taste.
Step 5: Slice & Serve
Slice rested tenderloin into ½" rounds.
Drizzle with warm pan sauce.
Garnish with fresh rosemary sprigs or cracked pepper for drama.