Make arugula pesto sauce: In a food processor pulse together all sauce ingredients except oil and water until arugula is chopped fine. With motor running add oil in a stream, blending mixture until smooth. Sauce may be made up to this point 1 week ahead and chilled, its surface covered with plastic wrap. Bring sauce to room temperature to continue. Stir in 1/4 cup hot water plus additional for thinner consistency if desired. In a 6-quart saucepan bring broth and water to a boil. Add chicken and simmer, covered, 9 minutes. Remove pan from heat and let chicken stand in cooking liquid, covered, until cooked through, about 20 minutes. Chicken may be poached 1 day ahead, cooled completely, uncovered, in cooking liquid, and chilled, covered. Bring chicken to room temperature to continue. Drain chicken and slice 1/4 inch thick. Serve chicken with sauce. Serves 6. Gourmet June 1995 Per serving: 1515 Calories (kcal); 76g Total Fat; (46% calories from fat); 189g Protein; 10g Carbohydrate; 411mg Cholesterol; 3832mg Sodium Food Exchanges: 1/2 Grain(Starch); 25 1/2 Lean Meat; 0 Vegetable; 0 Fruit; 11 1/2 Fat; 0 Other Carbohydrates Converted by MM_Buster v2.0n.