Keeping meat juices to make gravy My gravy making technique is hit-and-miss to say the least.  I tend to get the best results when roasting beef because it's rare.  That is, it's just roasts enough to cause the juice to come out.  What I find with other meats, especially chicken and pork (which need to be cooked for much longer) is that the potatoes and other veg that I roast seem to absorb the juices (which I see as a good thing), but then I have no juice left.

So, my question is this: how can I roast my potatoes and veg with the meat, but keep enough for gravy?  I really don't want to start roasting the veg in a separate pan.

I'm in the UK.  I mention this because I have visited America once, and the gravy seems to be far thicker there (more like a sauce than a gravy).
It sounds like you are trying to maximize the amount of pan juices, sometimes referred to be the French word jus.

Any piece of meat is only going to express so much jus; if you have potatoes or other absorbent vegetables in the roasting pan, they are going to absorb it and it won't be available for another purpose such as gravy.

What you still will almost always have is fond, the brown roasty bits at the bottom of the pan.  Many cooks deglaze the fond with a small amount of stock or wine to create the basis for a sauce or gravy, as the fond has a very rich and complex flavor&mdash;and its flavor may actually be enhanced by aromatic vegetables in the pan.