Is Julia so off re roast leg of lamb I followed the recipe



overshooting for the duration (2 hours) to aim for medium-well, but dispensed from using my (too slow to rise) thermometer. I ended up with



which is less than very appealing.

I know "individual ovens vary", etc... but this is off by a mile. Can you suggest how this might have happened?

Update

Please comment on the use of 350F for roasting a leg of lamb. One might roast at 425F, and keep in the oven for 60-90 minutes. Alternatively, one might use 275F, and keep the roast overnight in the oven. But what kind of cooking would you be aiming for if you used 350F?

Update 2

Yes, yes, she's a goddess. We love her. She inspired and inspires us. Etc.

But I'm not looking for a defence of Julia's wisdom. Nor am I looking for variables in the recipe (after reading "individual oven varies" on a thousand recipes, it sinks in to take it with a grain of salt).

Would you care to critique the recipe? George M says to up the temperature. That's a good start. What else would you change to get a lot of flavor yet a perfectly tender roast?
There are a lot of variables here:


Oven temperature: As you mention, this definitely can be plenty off, but honestly most newer ovens are all right and meat isn't the most sensitive thing to baking temperature. You'd probably have had other issue before if it were the cause here.
Meat weight/shape: Bigger means longer cooking times. The weight is a good first approximation, but the shape matters too: if the recipe was based on a flatter piece of meat, it'd have cooked faster.
The starting temperature: If the recipe was based on room temperature meat, but yours was chilled or previously frozen, it'll certainly take longer.


I'd guess your issue was more than just oven temperature, but it's hard to guess whether it's weight/shape or starting temperature or both.

In any case, as everyone seems to already be aware, the only real way to be sure is a meat thermometer. You're never really going to be able to find recipes that match your exact situation well enough to avoid this kind of thing otherwise.