Heat oven to 350°F. Spray 11x7-inch glass baking dish with non-stick cooking spray. In medium non-stick skillet, heat olive oil on medium-high heat. Add onions. Cook 2 to 3 minutes, stirring occasionally, until onions are soft. Add mushrooms. Continue cooking until mushrooms are soft. Remove from heat; stir in basil.
In medium bowl stir together eggs, salt and pepper. Stir in mushroom mixture. Pour into prepared baking dish. Sprinkle with cheese.
Bake 18 to 20 minutes, or until eggs are almost set. Cool slightly. Trim rounded edges off multi-grain wrap to make 7-inch square. Cut wrap into 49 (1-inch) squares, discarding one square. Cut baked frittata into 48 (1-inch) squares (cutting 8 crosswise; 6 lengthwise).
To assemble appetizer thread 1 square wrap, 1 square frittata and 1 half grape tomato onto toothpick. Continue with remaining ingredients to create 48 appetizers. Serve at room temperature.