Preheat oven to 450°F.

Make slits with a paring knife on all sides of the beef filet.

Insert thinly sliced garlic cloves into the slits.

Rub the beef filet with olive oil.

Press crushed black peppercorns onto the entire surface of the beef.

Place the beef filet on a rack in a shallow roasting pan.

Roast in the preheated oven for 15 minutes.

Reduce oven temperature to 350°F.

Roast for another 35 minutes, or until a meat thermometer inserted into the thickest part of the beef registers 130°F for rare.

For medium, cook for an additional 10 minutes, reaching 140°F.

Remove the beef filet from the oven and let it rest for 10 minutes before slicing and serving.