Preheat your oven to 450°F.

Line a rimmed baking sheet with foil or parchment paper.

Pat the beef tenderloin dry with paper towels.

Rub the tenderloin evenly with olive oil, minced garlic, chopped rosemary, thyme, salt, and pepper.

Spread the Dijon mustard evenly over the surface of the beef.

Heat a large skillet over medium-high heat until hot. Sear the tenderloin in the skillet, browning all sides for about 2 to 3 minutes per side.

Transfer the seared beef to your prepared baking sheet and roast in the oven for 20 to 25 minutes, until the internal temperature reaches about 130°F for medium-rare.

Let the beef rest for 10 minutes before slicing.

Place the skillet back over medium heat and pour in the beef broth. Scrape up any browned bits from the bottom of the pan.

Allow the broth to simmer for 5 to 7 minutes until reduced slightly.

In a small bowl, mix the softened butter and flour into a smooth paste. Gradually whisk it into the simmering sauce, cooking until the mixture thickens and becomes glossy, about 1 to 2 minutes.

Slice your beef into medallions, spoon the pan sauce over the top, and serve immediately.