I'd never had foie gras before, and while some may find it insane that my first taste would be at my own hands, the secret is out -- this may be the easiest gourmet food to make yourself, EVER. A restaurant in San Francisco is currently serving something extremely similar to this for $82/plate...way out of my price range, for sure. While foie gras isn't cheap, these two servings cost about $13...total. Of course, the figs came off the tree in our yard so they were free, but still...that's an amazing savings. At $45/pound, most people are scared away from trying to cook foie gras themselves; however, one appetizer serving (which, seriously, is all you need of this Richest Food on the Planet) is about 2-2.5 oz, so it's definitely affordable.
Foie gras, incidentally, does not come in a can. If you have foie gras in a can, it's a pate or some other mixture, and it will NOT sear! Even if your stepson brings you home a really great little tin of it from one of his trips to Paris and you can't read any of the french on the tin, trust me...it's not the kind of foie gras that sears (and no, I did not make this mistake because I can read french, but I know others who have done this). So don't make this rookie mistake...it will turn to mush...delicious, liquefied mush, but still, it's mush. Foie gras for searing comes from a very nice butcher, and will be wrapped in paper. It looks like slightly discolored, firm butter. If you know your butcher or you aren't worried that he or she will find you annoying, frustrating, and silly, try to ask for a center cut rather than an end cut.
When I made this, I prepared the mostarda at home, but saved the searing for our dining site...just a tiny portable stove and a tiny skillet is all it takes. Dress the greens and plate the dish right before serving. If you're so inclined, the classic pairing of foie gras and a good sauternes will knock your socks off.