Phyllo-Crust Chicken Pot Pie
["2 large skinless, boneless chicken breast halves", "2 medium potatoes", "1 onion", "2 c. frozen mixed peas and carrots", "2 Tbsp. salad oil", "1 tsp. salt", "1/4 tsp. dried tarragon leaves (optional)", "1 (13 3/4 oz.) can low-sodium chicken broth", "2 to 2 1/2 Tbsp. flour", "6 sheets phyllo", "1 Tbsp. butter, melted", "onion powder to taste (optional)"]
["Cut chicken breast halves into 1-inch chunks.", "Peel and cut potatoes into 1/2-inch pieces.", "Dice onion.", "In a 12-inch, high rim frying pan, over medium heat in hot salad oil, cook chicken, stirring frequently until tender and it loses its pink color. Remove with slotted spoon to plate.", "Preheat oven to 425\u00b0."]
["skinless", "potatoes", "onion", "carrots", "salad oil", "salt", "tarragon", "chicken broth", "flour", "phyllo", "butter", "onion"]