Unroll crescent dough into the bottom of a greased 9 x 13 baking dish. Press seams to seal, and press dough out to spread entire bottom of baking dish. Bake at 375 degrees for 13 - 15 minutes or until dough is lightly brown and crispy. Allow to cool completely.
Chop bacon and saute in a medium skillet until crispy. Drain on paper towels.
Whisk mayo and dijon. Spread evenly over cooled crescent dough. Top with lettuce, tomato, crumbled bacon, and sliced green onion. Serve immediately. Refrigerate leftovers.