Place The Squash And Peppers In An Ungreased 15-In. X 10-In. X 1-In. Baking Pan. Sprinkle With Rosemary, Salt And Pepper. Drizzle With 2 Tablespoons Oil; Gently Stir To Coat. Broil 4 In. From The Heat For 10-15 Minutes Or Until Tender, Stirring Every 5 Minutes. Meanwhile, In A Large Skillet, Cook Chicken And Garlic In Remaining Oil Until Chicken Juices Run Clear; Remove And Keep Warm. Add Broth And Onion To The Skillet; Bring To A Boil. Stir In Couscous. Cover And Remove From The Heat; Let Stand For 5 Minutes. Fluff With A Fork. Cut Chicken Into Strips. Serve With Couscous And Vegetables.