1. Heat the oven to 425F, and as it prepares, season the beef tenderloin roast with salt and pepper. Next, brown the tenderloin in hot oil on a skillet on all sides.
2. Mix the butter with mustard, garlic, thyme, and vinegar, then brush the mixture all over the roast. Place it in a pan and roast until the preferred temperature is reached (see chart above). Ensure to use a thermometer for this purpose.
3. Take the roast out and tent it with foil for 10 minutes, so the internal heat cooks it to the final temperature, then carve and slice for serving.

Also, here’s a video to help you further.