In a food processor, combine scallions, cilantro and garlic; process until finely chopped. Add avocado; process until smooth. Add yogurt, buttermilk. quarter cup water, lime juice, curry powder and red pepper to food processor; process until smooth. Cover and refrigerate at least 1 hour, until well chilled. Each half cup serving contains 115 calories, 5 gm fat, 104 mg sodium and 3 mg cholesterol.