In this Southern version of pesto, collard greens are used in place of fresh basil. Refrigerate leftovers up to one week. Cover tightly with plastic wrap to keep pesto a vibrant green.
Cook greens in boiling water to cover 3 1/2 to 4 minutes or until tender; drain. Plunge into ice water to stop the cooking process; drain well.
Process garlic and pecans in a food processor until finely ground. Add greens, oil, cheese, salt, and 1/4 cup water; process 2 to 3 seconds or until smooth, stopping to scrape down sides. (Mixture will be thick.