Notice a classic triangle formation at e4/c6/e8. Or examine forcing moves and arrive at the check Bxc6+. Ask what else the move attacks and you find the loose knight on e4. So Black moves his king and White wins the knight. That is the target-based way of seeing the solution; the pattern-based way would be to notice the triangular relationship between Black’s king, knight, and c-pawn, all on White squares. Stare at the diagram; contemplate its appearance.
Incidentally, what comes next after White plays 2. BxN? Now his bishop attacks both rooks—this time on the same diagonal—and so wins one of them as well. Again, you could see this by asking what the bishop attacks, or you could see it by scanning Black’s pieces for promising patterns and noticing that Black’s two rooks are on the same diagonal, just waiting to be forked if White can take the Black knight with his bishop. He can best do that by advancing on the knight in a way that also gives check (i.e., with Bxc6+), thus requiring Black to address the threat to his king rather than defuse the coming fork of the two rooks.