Nh6 certainly suggests itself almost instantly- it forces Bh6 and opens a line to g6 for white’s queen:
1. Nh6 Bh6
Well, if black does not capture, white just takes the rook at f5 with a material edge and a strong initiative. Continuing:
2. Qg6 Kf8 (Bg7? 3.Qe6!+-) 3. Qh6 Ke7 (Ke8 4.Qe6)
And now, white has won a pawn and has a strong attack. Looking at the position here, I think white probably does best to continue with Qh4-Bh5:
4. Qh4 Ke8 (Kf8 5.Qd8+-) 5. Bh5 Rh5 (Kf8 6.Qd8 Kg7 7.Rg1) 6. Qh5 Kd8 and black’s king will escape to the queen side, but at the expense of a pawn and an exchange.
Nh6 certainly suggests itself almost instantly- it forces Bh6 and opens a line to g6 for white’s queen:
1. Nh6 Bh6
Well, if black does not capture, white just takes the rook at f5 with a material edge and a strong initiative. Continuing:
2. Qg6 Kf8 (Bg7? 3.Qe6!+-)
3. Qh6 Ke7 (Ke8 4.Qe6)
And now, white has won a pawn and has a strong attack. Looking at the position here, I think white probably does best to continue with Qh4-Bh5:
4. Qh4 Ke8 (Kf8 5.Qd8+-)
5. Bh5 Rh5 (Kf8 6.Qd8 Kg7 7.Rg1)
6. Qh5 Kd8 and black’s king will escape to the queen side, but at the expense of a pawn and an exchange.