Heat oven to 425°F. Line cookie sheet with foil; spray foil with nonstick cooking spray. Sprinkle with cornmeal.
Spray medium nonstick skillet with cooking spray. Heat over medium-high heat until hot. Add chicken; cook and stir 5 to 6 minutes or until no longer pink. Add onion and garlic; cook 1 to 2 minutes or until onion is tender.
Stir in pizza sauce and Romano cheese. Remove from heat; stir in spinach and mozzarella cheese.
Remove pizza dough from can; do not unroll. Cut roll of dough into 4 equal portions. Press or roll each portion into 6 to 7-inch round.
Spoon 1/4 of spinach mixture onto half of each round. Fold untopped half of dough over filling; press edges together with fork to seal. Place calzones on cookie sheet; reshape into semicircles, if necessary. If desired, spray tops lightly with cooking spray.
Bake at 425°F. for 10 to 15 minutes or until crusts are golden brown.