how long to cook 3 pound standing rib roast???

It's best to use a thermometer to get to med-rare, 130F.

My estimate at 350F will take about 90 minutes... then start checking temperature.

What temperature is the oven set at?

Did the roast come to room temperature or did you go from refrigerator to oven?

At this point, just rely on the thermometer to get you to the doness you want.

Good luck

If you cook it at 300 to 325 degrees, in an open roasting pan, fat side up, and allow about 18 to 20 minutes

per pound, for rare, 22 to 25 for medium, and 27 to 30 for well done, it should work out fine. That's how I've always done mine.

Preheat oven to 450 stages. Rub roast with a smashed garlic clove or 2. Season with salt and pepper, then dredge it in flour. place roast fat edge up on a rack in baking or roasting pan and place in preheated oven. Roast at 450 for one one million/2 hour then decrease oven temp to 325 stages. proceed roasting till inner temperature of the roast reaches one hundred thirty five-a hundred and fifty (depending on wanted doneness). Temperature will upward thrust approximately 5 stages upon resting meat. enable relax for approximately quarter-hour to enable the juices redistribute, then carve and serve. be advantageous to truly have a rib roast there as maximum different "roast" cuts of beef are too difficult for dry cooking and could be braised.