Heirloom Tomato Tarts

I saw this being made and it looks delicious.

• Ready In: 1 hr 30 mins
• Serves: 6
• Yields: 6 tarts

Ingredients

• Pastry

• 2  cups flour
• 2  cups butter

• Filling

• 3  tablespoons stone ground dijon mustard
• 1  cup white cheddar cheese, aged, grated
• 2  cups  caramelized onion
• 4  large  heirloom tomatoes, sliced and cut into wedges
•  kosher salt, to taste
•  fresh ground pepper, to taste
• 3  tablespoons fresh basil, thinly sliced
• 1  egg, beaten

Directions

1. Make pastry and chill for about 30 minutes.
2. Prepare caramelized onions by slicing thin and frying in 2 - 3 T olive oil on medium to medium low until almost black. Should not be too oily.
3. While onions are cooking, bring out pastry and cut into six inch circles.
4. To assemble the tarts spread the center of the pastry circles to taste with mustard, top with a couple tablespoons of grated cheese, then top that with onions to taste and the add the tomato wedges, about 4 wedges per tart.
5. Pull pastry edges over tomatoes and pinch to form rustic tart.
6. Top each tart with a bit of the basil and fresh ground pepper and kosher salt.
7. Brush pastry with egg wash and bake 375 degrees for 30 to 45 minutes. Cool.
8. Can be served Room temperature.