Wow! put in at 45o degrees and checked in 50 minutes--my bad--skin burned black over breast and legs!
Should have known better.
Will try another at 375.
Have done Ina Gartens perfect roast chicken at 400 with good results, though.

The best turkey I have ever roasted. Thanks to some comments, I did a very quick clean of my oven first to avoid any smoking. Even when I left the turkey in the oven 10 or so minutes longer than I needed to, it was the most moist and delicious turkey I may have ever tasted, let alone made. I will never roast turkey any other way. Thank you.

To Karen16, I'm sorry that happened to your house. I did a lot of research on spatchcocking prior to roasting mine, and I found that the fat on the pan can sometimes smoke up. An easy solution I utilized was placing the turkey on a bed of onions, which not only flavored the meat and pan juices wonderfully, but it kept the pan moist enough to avoid smoking. Hope you give it another chance sometime!

I will never make a turkey any other way again! The breast meat was so tender and juicy and it cooked up so fast. I had a 14-pounder and it was done in 80 minutes! I thought I would miss the spectacle of bringing a whole turkey to the dinner table and the ooh's and ahh's, but i took the time to carve and arrange it beautifully and I would say that my guests were equally as impressed, if not more when they tasted it! Make this next Thanksgiving!

Roasting your turkey or chickens using this method always comes out juicy and crispy. And the cooking time is reduced so I don't feel like I have to get up at 4:00 AM to have Thanksgiving Turkey ready by 1:00. LOVE IT!

We tried this 2 yrs ago with a 22 lb turkey. We cooked it on our Weber grill at around 375 and used the cookie sheet. It was a big hit and very juicy. My sis-in-law did it the next year and added fresh herbs w/ olive oil under the skin. It turned out perfect and the oven was free for all the other side dishes.

My open-concept house is now full of greasy smoke. 450 degrees????...This is a turkey not a pizza! I reduced the temp. and legnthened the time so I can breath. Perhaps I missed something. I am glad that I tried this on a non-holiday day! Oh my! Clean up will take several days.

I usually always to a large 20lb or bigger bird this way, very successfully. It takes about 2-2.5 hours; use a thermometer as Martha suggests for your first time. I have tried it on a flat wire rack and it gets done faster, but I like the flavors that it absorbs when you lay it over herbs and veggies. Then I puree those vegies to thicken my gravy. I'll be honest....I do not like white meat at all...but I'll eat this it's so moist!

I agree with SJRL, cook two 12 pound turkeys, just as easy an the white meat won't dry out so much as with a huge bird. And not so blasted heavy when lifting each bird separately. I thought about brining my turkey this year, but could not get one smaller than 14 pounds, so will be spatchcocking it instead, it is just so much easier to me.

I don't know that I would ever do a 21 pound turkey - I'd rather do 2 10-12 pound turkeys. A 21 pounder is likely to dry out regardless of method before it cooks through.

Can this be done with a 21 lb turkey? How long would it take in the oven?