Puff Pastry - Either store bought or homemade. Here's a good recipe.
2 T Olive Oil
3 Leeks, sliced thin
4 t mixed, fresh herbs (basil, thyme, rosemary, oregano, your choice)
1/2 t salt
1/2 t pepper
3 Tomatoes, sliced
4 Cloves garlic
1/2 c Parmesan Cheese

Rinse a baking sheet and let the excess water drain off. Do not dry.

Roll the pastry into a 16x12 inch rectangle, 1/4" thick. Place the dough onto the wetted baking sheet.

Preheat an oven to 400 degrees.

Heat the olive oil in a heavy skillet over moderate heat. add the leeks, herbs, salt and pepper and cook until softened and starting to turn golden. 10 minutes. Stir in the garlic, cook for one more minute then remove from the heat.

Sprinkle the cheese evenly over the pastry. Place the leeks over the cheese and then top with the sliced tomatoes, overlapping slightly. Turn the corners and edges of the pastry over the filling. Brush the entire dish with olive oil. Bake until the pastry is golden and crisp, about 30 minutes. Remove from the oven and sprinkle with extra cheese and herbs if desired.