On silpat (or parchment) roll out one crust worth of dough an 11" circle and place on baking sheet (some of the dough may drape over the edge; this will be folded over the filling). Combine Monterey Jack with mozzarella and spread over center of dough circle, leaving a 2" rim. Sprinkle most of the basil over cheese, then top with tomato slices. Fold edges of dough up and over filling; there will be a 1-2" gap in the center. Sprinkle remaining basil into the gap.
Bake galettes in preheated 400°F oven for 20 minutes or until golden brown. Cool about 10 minutes before serving.