Preheat the oven to 375°F (190°C).
In a medium bowl, combine cooked bacon, chopped tomato, green onions, shredded Swiss cheese, and mayonnaise. Mix well.
Place phyllo shells on a baking sheet.
Fill each shell with about a tablespoon of the bacon mixture.
Bake for 15–20 minutes, or until the filling is bubbly and the tops are lightly golden.
Serve warm or at room temperature.