The butter should now be nicely browned and nutty tasting/smelling, and the sage leaves should be somewhat crispy. Remove from the heat, and hit with about a tsp on lemon zest and lemon juice. Pour into a bowl and hit with a little bit of finishing olive oil, and stir to combine.
I've given up on getting the sage to crisp. It happens like 1/30 times, even when the browned butrer otherwise turns out great.
The secret? It's gotta be dry. I mean like bone dry. I like take mine out early, cut it, salt it, and let it sit, then dry it off again before I put it in.
I'll try that regimen next time!
Ladle it over your gnocchi, tortellini, ravioli, whatever. Top with some parmesan and maybe another hit of lemon juice if you need some more acid.