Heat a large nonstick skillet over medium-high heat. Coat pan with cooking spray. Add chicken to pan; sprinkle with salt. Sauté 5 minutes or until browned and done.
While chicken cooks, bring 2 1/2 cups broth and bay leaf to a boil in a large saucepan. Add potatoes; cover and cook over medium-high heat 8 minutes. Stir in peas and carrots; cover and cook 2 minutes. Stir in chicken. Combine remaining 1/2 cup broth and flour; stir into potato mixture. Reduce heat to medium; cook 2 minutes or until bubbly and thick. Remove bay leaf. Stir in thyme, pepper, and sage.
While potato mixture cooks, cut piecrust dough crosswise into 12 strips. Arrange on a parchment-lined baking sheet. Bake at 425° for 7 minutes or until browned and puffy. Top chicken mixture with piecrust strips.