Not a spirit, but I would serve red wine. In particular a Barbera d'Alba or maybe a Chianti. Red Italian wine seems appropriate and those two are good with pasta in my opinion. It does depend a bit on the kind of lasagna. I'm assuming the standard red tomato sauce kind.
What spirit goes best with lasagna?
Whiskey or bourbon would be my recommendation for pairing spirits with lasagna. Both go well with pasta dishes and Italian foods in general.
If you prefer beer, please check this out: What's a good beer to go with lasagna?
If you desire wine being paired with lasagna the following may be helpful: 10 Wines that Pair ...