Place beans, garlic, and lemon juice in the workbowl of a food processor fitted with a steel blade. Pulse until beans are roughly chopped.
With motor running, slowly pour ¼ cup of oil through feed tube. Process until mixture is smooth.
Transfer bean mixture to a small bowl. Stir in rosemary, lemon zest, and remaining 1 tablespoon of oil. Season with salt and pepper to taste. Serve immediately or store in an airtight container in the refrigerator for up to 3 days.
