Break or chop leftover turkey into small cubes.
Place turkey in a large bowl and coat with olive oil spray.
Add the garlic, cayenne, red pepper flakes and garlic salt and mix together so that spices evenly coat turkey.
In large saucepan over medium-high heat, saute turkey for no more than 2 minutes, just enough to sear and allow seasonings to penetrate.
Remove sauteed turkey from heat and set aside.
Bring the chicken broth and water to a boil in a large Dutch oven (or spaghetti pot).
Stir in the celery, carrots and onion, bring to a boil, and boil on medium heat for 15 minutes.
Add the turkey and cook another 5 minutes, then add the orzo and boil for 4 more minutes.
Turn off the heat and stir in the pesto and lemon juice. Add the Parmesan cheese and stir again.
Serve with two slices of toasted whole wheat sourdough.