Chef Style is also referred to as “oven-prepared.”
The entire beef rib cut, before it is cut up into various portion cuts, is called the “primal rib” (as it is the first or “primal” cut.)
Oven-prepared beef rib has the following items cut away from it, before any actual smaller portion cuts are made: blade bone, cartilage, short ribs and chine bones.
A Chef Style Roast or steak is one that has been cut from the rib following that preparation. An ordinary Prime Rib Beef Roast is cut from the primal before that preparation.
Count on about 2 servings per rib.
Dry roast in oven at 350 F (180 C), allowing about 18 minutes per pound for medium-rare, 20 minutes for medium and 24 minutes for well-done. Using an instant-read meat thermometer, cook to 145 F (63 C) for medium-rare, 160 F (71 C) for medium, and 170 F (77 C) for well-done. When cooked to the point that you want it, remove from oven and let the meat rest, covered for about 15 minutes before slicing and serving; for a Rib Roast of 4 or 5 ribs, let rest for 30 minutes, covered.
Or use “Ann Seranne’s Method for Rib Roast of Beef.”