Step #1 The evening before; slice small slits all over the roast then stuff with the garlic clove halves.
Step #2 Rub the roast all over with oil, then brush the top & sides of the roast with the mustard, then sprinkle with thyme & and black pepper.
Step #3 Place into a shallow roasting pan, do not use a rack set directly on the pan (if any fat on the roast place it fatty-side up in the pan).
Step #4 Cover up with plastic wrap & put in the fridge 24 hrs or up to 2 days (careful not to remove the mustard mixture on the roast with the plastic wrap).
Step #5 The following day remove the roast from the fridge, uncover & discard plastic wrap.
Step #6 Let sit out on the counter to bring down to about room temp (this might take a couple hrs or more, it is an IMPORTANT step to relax the meat fibers to create a more tender juicy roast).
Step #7 Set oven to 450 degrees.
Step #8 Pour 1 c beef broth into the roasting pan.
Step #9 Roast uncovered for 20 mins in a preheated 450 degree oven.
Step #10 After 20 mins of cooking reduce the heat down to 325F degrees.
Step #11 Cook roast until desired doneness (please keep in mind, & after the 20 mins cooking time at 450 degrees, these times are for a 3-lb roast, you will need to adjust cooking time for larger roasts!).
Step #12 For a rare roast 50 mins more cooking time.
Step #13 For medium-rare 60 mins more cooking time -- 70 mins for medium & 80 mins for medium-well.
Step #14 When the roast is cooked remove this from the pan & set on a plate; tent with foil wrap to prevent drying out.
Step #15 To make the Jus set the roasting pan on stove top over med-heat/flame.
Step #16 Add in 3 c beef stock, using a wooden spoon scrape the bottom of the pan to release the browned bits, carefully simmer for 4-5 mins (adjust the heat downwards so that the Jus maintains a gentle simmer.
Step #17 Using an electric knife (if you have one) or a sharp carving knife slice the roast as thinly as possible & serve this with the au Jus.
Enjoy the Mustard & Thyme Baron of Beef Au Jus recipe