In a food processor, add flour salt, and sugar and pulse until incorporated. Add butter and shortening and pulse until it becomes crumbly. Slowly add in egg yolk that has been mixed with cold water to the mixture and pulse until a dough forms. If the dough seems dry, you can add more cold water starting at 1 tablespoon at a time.

Gather dough in a ball and let rest for 30 minutes in the refrigerator.

Preheat oven to 375 degrees.

Roll out dough into a 9-inch tart pan and line with parchment paper and baking weights or beans. Bake for 10 minutes

Slice nectarines into a bowl, cut into eighths. Add lemon juice, and vanilla extract and mix until incorporated.

Take dough out of the oven, and add the peach jam to the bottom of the crust. Arrange fruit skin side down in a pattern starting with the outside and working your way inside. Brush with melted butter and sprinkle with sugar.

Bake for 30-35 minutes until crust is browned and fruit has gently cooked.

Serve!