This is a recipe for the traditional French mustard tart. There are only a few ingredients: pastry, tomatoes, Dijon mustard, a bit of Swiss cheese, and a sprinkle of thyme. This recipe is an adaptation of recipes from Food Republic and a tiny Maille recipe book owned by a friend.
As you’ll see, the recipe calls for salting the tomatoes to wick away excess liquid. When I made this last week I used Roma (plum) tomatoes, which are meaty and generally not watery. I did not salt them and the tart was perfect. So use your judgment based on the condition of the tomatoes you use. Whole Foods carries an all-butter puff pastry (DuFour Classic Puff Pastry) that is much more delicious than other brands that use vegetable shortening. But use what you can find. This probably would work with pizza dough, too, or with pie pastry, although you’d need to adjust the baking time.
French Tomato Tart
- 5-6 (or more) ripe tomatoes, preferably plum/Roma
- 2 tablespoons Dijon mustard
- 2/3 cup shredded Gruyere or Emmentaler cheese
- 1 package puff pastry, thawed
- A bit of butter
- 1 teaspoon fresh thyme leaves, chopped
- 4 tablespoons butter
- Sea salt
- Extra virgin olive oil
- Preheat the oven to 400 degrees. Slice the tomatoes in 1/4 inch slices.
[If salting: Salt heavily. This is so that excess water comes out of the tomatoes and keeps the tart from getting soggy. Leave the salted tomatoes aside for ten minutes. After ten minutes, use a paper towel to wipe off extra salt and moisture from the tomatoes.]
- Coat a tart pan with removable sides with a little bit of butter. Arrange the puff pastry in the pan. Use a pie or regular baking dish if you don’t have a tart pan.
- Spread the Dijon evenly over the pastry, then sprinkle the cheese. Arrange the tomatoes in overlapping circles on top of the mustard and cheese. Dust with a bit of sea salt if tomatoes were not salted earlier. Scatter thyme over the tomatoes.
- Drizzle no more than a tablespoon of EVOO on top.
- Bake for 45 minutes or until the tomatoes just begin to char around the edges and pastry is a deep caramel color. Allow to cool for a few minutes before slicing and serving.
Serves 6 to 8