So imagine my chagrin when my 15lb prime rib roast came home boneless....... I'm a roast on the bone kind of girl so now I'm a bit lost. I will be cutting this about in 1/2 so I will actually be cooking about 8 lbs.(12 people). I usually sear first then slow roast, but I heard somewhere(was it cook's illustrated?) that roasting first then searing eliminates the grey overcooked ring around the roast. So I'm contemplating 250 till we reach 125 then removing the roast, cranking the heat to 500 then returning the roast to the oven for 10 or so minutes. Any food for thought??