Preheat oven to 400 degrees Fahrenheit. Slice tomatoes thick, about 1/4 inch. Salt and pepper the tomatoes and let sit. This will dry off some of the liquid in the tomato and prevent the finished galette from being too soggy. On a floured pastry board (I use a sifter to flour my board since it results in more evenly distributed flour), roll out the dough to an 8-10 inch round about 1/8-1/4 inch thick.
Source: Heirloom Tomato Galette