1.Nh3 f6 2.e4 d5

The critical move is 3.Na3.

White can also try:

3.d4 Na6,

3.Nc3 b5 4.d4 Bg4 (or 4...Nh6 5.Bxh6 e5 6.exd5 Bg4 7.f3 Bd6) 5.f3 Bxh3 6.exd5 e6.