Use a tart pan with a removable bottom. Roll out dough so that it will fit into the tart pan. Lightly press it into the pan, then roll a rolling pin over the top of the tart pan to trim the edges of the crust.
Put a layer of parchment or tin foil into the tart and fill with ceramic pie weights or dried beans. Cook for 20 minutes at 375F.
Remove the pie weights and allow the tart shell to cool. Once cool, spread mustard in a thin layer on the base of the tart shell.
Layer in your tomato slices in a concentric circle.
Top with pieces of goat cheese and herbs.
Cook at 350F for 20 minutes or until the cheese is golden on top.