1. Cook turkey pieces in hot oil in a Dutch oven over medium-high heat 6 to 8 minutes on each side or until lightly browned. Add onion and celery, and sauté 4 minutes. Gradually stir in chicken broth, stirring to loosen particles from bottom of skillet; stir in parsley. Bring to a boil; cover, reduce heat to medium-low, and simmer, stirring occasionally, 30 minutes. Pour mixture through a wire-mesh strainer into a large bowl, discarding solids.
2. Melt butter in Dutch oven over medium heat; whisk in flour, and cook, whisking constantly, 1 to 2 minutes or until mixture is golden and smooth. Gradually whisk in broth mixture; increase heat to medium-high, and bring to a boil. Reduce heat to medium, and simmer, stirring occasionally, 15 to 20 minutes or to desired thickness. Stir in remaining ingredients.