Heat oven to 425°F.
If using crescent rolls: Unroll dough into 2 long rectangles. Place 3 inches apart on ungreased cookie sheet. Firmly press perforations to seal. If using dough sheet: Unroll dough and cut into 2 long rectangles. Place 3 inches apart on ungreased cookie sheet.
Press to form two 10x3-inch strips, forming rim around edge of dough. Spread each strip with 1 tablespoon pesto. Top each with tomatoes, onion and rosemary. Sprinkle each with mozzarella and Parmesan cheese.
Bake 10 to 14 minutes or until edges are golden brown and cheese is melted. Cut each into crosswise slices. Serve warm or cool.