The most reliable fix is **dilution**: there isn’t a general-purpose ingredient that will cancel garlic’s sharpness without changing the pesto.

Since you’re out of basil, try adding:

- **More nuts and Parmesan**, a little at a time. These increase the amount of pesto and balance the garlic with richer flavors.
- **Parsley or baby spinach**, if available. They’ll dilute the garlic while keeping the sauce green, though they’ll change the flavor.
- **A little more olive oil**, along with those additions. Too much oil alone will make the pesto greasy.

You can also use less pesto per serving and stretch it with pasta water, or mix it with ricotta for a milder, creamy sauce.

A small squeeze of lemon may improve the overall balance, but it won’t reliably remove the garlic bite; taste a spoonful with a few drops before adding it to the whole batch.

For your next batch, start with less raw garlic and taste before adding more. Blanching or roasting the garlic first will also give you a gentler flavor.