This lightened-up version of your comfort food favorite replaces a traditional flour and butter roux with cornstarch and heavy cream, plus a touch of reduced-fat cream cheese.
1. Preheat oven to 450°F. Dice the chicken into ½-inch chunks. In a 10- to 12-inch ovenproof skillet, heat the oil on medium-high. Add the chicken and season with salt and pepper. Cook 6 min., until browned, stirring occasionally. Transfer to a bowl.
2. To same skillet, add the celery and onions. Reduce heat to medium. Cook 6 min., until vegetables are translucent, stirring often.
3. Meanwhile, in a medium bowl, whisk together the cornstarch and ½ cup of broth until smooth. In a small bowl, whisk the egg and 1 tbsp water. Unroll the pie crust and brush all over with egg wash. With a 3-inch heart-shaped cookie cutter, cut a heart from center of crust. Arrange cutout next to heart-shaped hole.
4. To skillet, add the cream cheese and remaining 2 cups broth. Whisk until cream cheese melts. Stir in the frozen vegetables, chicken, parsley, and cornstarch mixture, scraping up any browned bits on bottom. Heat to a simmer on high. Simmer 1 min., until thickened. Season with salt and pepper to taste.
5. Arrange pie crust over filling, tucking in edges. Place entire skillet in oven. Bake 15 min., until mixture is bubbling and pastry is golden brown.