What foods can you get in the us but not in the uk?

You've barely touched on the regional foods: jambalaya, Texas red (real chili), chitlin's, clam chowder (both New England and Manhattan), sourdough, succotash, sandwiches on long rolls (po'boys, hoagies, subs, heros, and other names, depending on the region), and a wide assortment of beers (some of which are actually in a class with the best ales from the UK). If you are planning on shipping things to your friend, you are pretty much limited to food that is canned or dry. Pity.