Place parsley and mint leaves in a food processor, and pulse 2 to 3 times or until combined. Add anchovy and next 5 ingredients (anchovy through black pepper); process until well-blended, scraping sides of processor bowl occasionally. Add ricotta; process until smooth. Spoon parsley mixture into a mixing bowl; stir in yogurt, sour cream, and onion.
Sprinkle gelatin over water in a sauce-pan; let stand 1 minute. Cook over low heat; stir until gelatin dissolves. Remove from heat; cool slightly. Stir into parsley mixture. Cover and chill. Garnish with parsley sprigs, if desired. Serve with Pita Chips.