Heat oven to 350 F. Lightly coat a baking sheet with cooking spray.
In a large, nonstick frying pan, heat the olive oil over medium-high heat. Add the chicken and saute, turning occasionally until golden brown, about 10 to 12 minutes. Set aside to cool. When cool to the touch, cut the chicken breasts into cubes. Set aside.
In a small bowl, combine the spinach, ricotta cheese, garlic, parsley, Parmesan cheese and 1 of the egg whites. Mix until well blended. Set aside.
In another bowl, use a wire whisk or fork to lightly beat the remaining egg white.
Cut the bread dough into 6 equal-sized pieces. On a floured surface, press each piece into a circle. Using a rolling pin, roll each dough piece into ovals 8 inches long and 6 inches wide. Brush the edges of the dough ovals with the lightly beaten egg white. Place 1/6 of the chicken cubes in the center of each oval. Add 1/6 of the spinach mixture to each. Fold the dough over the filling, pressing the edges together. Crimp with a fork and place on the prepared baking sheet.
Bake until browned and crispy, about 15 to 20 minutes. Serve immediately.