as others have said long gold short eur.usd that makes him dollar neutral if usd goes down he wins on the gold and probably loses on the short eur if usd goes up he loses on the gold and wins on the short eur but he's more bearish on eur than he is usd
I always laugh when they say to put no more then 5 or 10% of your funds in a given investment. Then they go on to say that one should invest no more then X% of their money? (x>10) Its amazing how investing in the dollar is regarded as "saving".
If he is more bearish the euro he will loose money is the euro goes up, and make if it goes down. So why not skip all the drama and simply put a small position to short the euro?