an immersion circulator, 12-inch cast-iron skillet, one-gallon zip-top freezer bag
Install an immersion circulator in a water bath and set it to 135 degrees F.
Trim any fat and sinew from the exterior of the roast, but don't discard it.
Heat a 12-inch cast-iron skillet over high heat for 5 minutes. Brush or rub the roast with the oil and season the roast on all sides with the salt.
Thoroughly sear the roast on all sides, about 2 minutes per side. Add the trimmings to the skillet and brown alongside the roast.
Combine the Worcestershire, Dijon, garlic powder, onion powder and pepper in a one-gallon zip-top freezer bag.
Transfer the seared roast and trimmings to the freezer bag and squish the sauce around to coat. Remove as much air from the bag as possible and seal tightly. Place the bag in the water bath, making sure the meat is completely submerged (see Cook's Note). Cover the water bath with plastic wrap to prevent evaporation.
After 10 hours, retrieve the bag from the water bath, discard the fatty bits and remove the roast to a carving board. Strain and reserve the jus. Thinly slice the beef across the grain and serve with the jus.
If the bag refuses to sink, even after you try sucking out the air, consider adding some weight to the bag. I keep a couple of 1-inch diameter stainless steel ball bearings around for just such a use.