Unfold the pastry and gently roll into a larger thinner rectangle on a silpat or parchment paper. Transfer to a baking sheet.
Score the dough about 1/2-1 inch from the edges all the way around. Turn up dough and crimp to form the edge of the tartine.
Bake at 400 for 10 minutes until starting to brown. Remove from oven.
Spread with a layer of mayonnaise and sprinkle with 1/2 of cheese.
Arrange bacon pieces on top of cheese and top with drained tomato slices.
Spread a scant amount of pesto over tomatoes. Too much pesto will make this tart too oily.
Top with remaining cheese and bake at 400 15-25 more minutes until everything looks golden and melted.
Remove from silpat or parchment to cutting board.
Top with basil leaves, lettuce and drizzle with a little bleu cheese dressing.
Cut into pieces to serve. Makes 2-4 servings