Cook pasta according to package directions, adding beans for the last 2 minutes of cooking time. Remove 1/2 cup of the cooking liquids; set aside. Drain pasta and beans; cover to keep warm.
Meanwhile, finely shred peel from the lemon half (about 2 teaspoons). In a small skillet heat 1 tablespoon of the oil over medium heat. Add lemon peel; cook and stir 1 minute, or until lightly golden.
Combine cooked lemon peel, pesto, the remaining 2 tablespoons olive oil, the juice from the lemon half, 1/2 teaspoon salt, and 1/4 teaspoon pepper. Add reserved cooking liquid, 1 tablespoon at a time, stirring until desired consistency is reached.
To serve, toss hot cooked pasta mixture with lemon-basil mixture. Makes 4 servings.