Spray counter lightly with non-stick cooking spray. Combine rolls and roll into a 12-inch circle. Place on a large sprayed baking sheet.
In a bowl, combine cheeses and basil. Spread cheese mixture evenly over dough, leaving a 2-3-inch border all around. Top with sliced tomatoes and salt and pepper. Fold the 2-3-inch border of dough up over filling, pleating as you work your way around the tart. Brush crust with olive oil and secure in a few spots with toothpicks if necessary.
Bake at 325°F 35-40 minutes.
Gruyère is a hard yellow cheese made from cow's milk, named after the town of Gruyères in Switzerland. See http://en.wikipedia.org/wiki/Gruyère_(cheese)