Store bought puff pastry
1 small onion, sliced
2 tomatoes, sliced
Over medium high heat, caramelize the onions, set aside. Add bacon to the pan, and cook until done.
Assemble the tart, roll out the puff pastry in a rectangle and fold in the edges. Place caramelized onions on the bottom, then crumbled bacon, and top with sliced tomatoes.
Bake until done.