Hi Madelaine, Wow that’s a huge tenderloin! Ok, I want you to get this right, but I have never attempted to make such a large piece. That being said, I have spoken to my team and we have brainstormed some ideas. You will want to buy double the mushrooms and prosciutto to cover that extra length, and you will definitely need at least double the quantity of puff pastry (may need more just in case). You can simply overlap the pastry sheets slightly and press the seams together to create one long rectangle large enough to encase the entire log.

The most important trick for roasting the whole 4.25 lb loin is to manage the tapered end so it doesn’t dry out. You should perform a tail tuck by folding the thin, tapered end of the meat underneath itself to create a uniform thickness along the entire length of the roast. You can tie this section with kitchen twine to hold the shape while you sear it—just remember to remove the string before wrapping it in the pastry!

Finally, be prepared for a slightly longer cook time due to the increased mass, likely around 45 to 55 minutes. However, because the pastry acts as an insulator, it is crucial not to rely solely on the clock. Start checking the internal temperature around the 35-minute mark and pull it out of the oven exactly when it hits 125°F (52°C) in the center. This will ensure you get that perfect medium-rare doneness from end to end for your hungry guests! Please let me know how it goes, and have a Merry Christmas with your family! Xx

Hi Lina, You definitely should give it a go! The taste is incredible and so indulgent! Please let me know how you go! Xx