1.Nh3 f6 2.Nc3 c6 3.e3

The critical move of this line is 3...d5.

Another choice is 3...e6 4.Nb5 (or 4.Nf4; 4.Bd3) 4...Bb4 (4...cxb5 is losing after 5.Qh5+ g6 6.Qb5 Nc6 7.Qb6 followed by Bb5 and Nf4) 5.c3 Nh6 6.Nc7+ Kf8.

The lines with 3...g6 and 3...h5 seem dubious and white will reach a winning position with 4.Ng5 (maybe 4.Nb5 works too).