Pulse the garlic and the almonds in a small food processor.
Add the chives, basil, lemon juice, and salt. Pulse until everything is roughly chopped.
Stream in the olive oil, ¼ cup at a time, until the pesto is light and smooth - the consistency of mayonnaise. You might need less than ½ cup total. Taste for seasoning and add more salt as necessary.
Serve on crostini, or as part of this roasted potato salad.