- 2 to 3 lb beef tenderloin, room temperature
- 1 tbsp olive oil
- 1 tsp garlic powder
- Kosher salt
Red wine sauce
- 1/4 c butter
- 1 c onion, julienne cut
- 1/2 tsp sugar
- 1 c red wine
- 1 c beef broth
- 1 tsp dried rosemary
Preheat the oven to 450 degrees. Brush the beef with olive oil. Season with garlic powder and generously sprinkle salt and pepper over all. Set the beef on a rack placed on top of a foil-lined baking sheet. Roast the beef until a thermometer reads 120 degrees for rare, about 25 minutes; 130 degrees for medium-rare, about 30 minutes; 140 degrees for medium, about 40 minutes. Wrap the beef in the foil and allow it to rest for 15 minutes (the temperature will rise 5 degrees as the beef rests).
Meanwhile, make the sauce. Melt 2 tbsp of the butter in a large skillet over medium heat. Add the onions and sugar. Cook and stir occasionally until brown, at least 10 minutes (I caramelized mine for 40 minutes). Add the wine and broth to the skillet, scraping up any browned bits. Bring to a boil over medium-high heat. Boil until the liquid is reduced to 1 c, about 10 minutes. Reduce the heat to a simmer and add the rosemary. Stir in the remaining 2 tbsp butter.
Unwrap the tenderloin and set it on a carving board. Pour all of the accumulated juices into the sauce. Season the sauce with salt and pepper, to taste.
Slice the meat and serve it with the sauce.