Garlic scape pesto

This is my version of a recipe originally posted by mightyh over on the Cooking Light bulletin boards.

Yield: About 1 cup

6 fresh garlic scapes
1/2 cup grated Parmesan cheese (about 2 ounces)
2 tablespoons pine nuts
1 scant teaspoon lemon zest
1/2 ounce fresh basil leaves (about 1 loosely packed cup)
1/3 cup extra-virgin olive oil, plus more if needed
Salt to taste

Trim the buds from the top of each garlic scape and roughly chop. In a food processor or blender, pulse the scapes with the cheese and pine nuts until finely chopped. Add basil and lemon zest; process until incorporated, scraping down sides of bowl as needed. Add olive oil one tablespoon at a time, until pesto reaches desired consistency. Season to taste with salt.