Bring broth to a boil in a large Dutch oven. Add peas and next 5 ingredients to pan; cover, reduce heat, and simmer for 6 minutes. Add chicken and cook 5 minutes or until chicken is done. Remove chicken and vegetables from broth with a slotted spoon and place in a large bowl.
Increase heat to medium. Weigh or lightly spoon flour into dry measuring cups; level with a knife. Place all but 1 tablespoon flour in a medium bowl; gradually add milk to bowl, stirring with a whisk until well blended. Add milk mixture to broth; cook for 5 minutes or until thickened, stirring frequently. Stir in chicken mixture, parsley, and next 3 ingredients. Spoon mixture into an 11 x 7inch baking dish coated with cooking spray.
Sprinkle remaining 1 tablespoon flour on a work surface; roll dough into a 13 x 9inch rectangle. Place dough over chicken mixture, pressing dough to seal at edges of dish. Cut small slits into dough to allow steam to escape and coat dough lightly with cooking spray. Place dish on a foil-lined baking sheet. Bake at 400° for 16 minutes or until pastry is browned and filling is bubbly.
let your toddler help by: Identifying and locating the vegetables. Helping roll the dough.