For the Pie Crust (makes 2 pie crusts):
In the bowl of a food processor, pulse together the flour and salt.
Add the butter and continue to process until it resembles a coarse meal.
With the machine running, slowly add the water and process until a dough comes together.
Add more water if the dough seems too dry.
Remove the dough from the food processor, divide it into two equally-sized balls, and flatten them into disks.
Wrap each disk in plastic wrap and chill for at least one hour before rolling it out.
Roll one of the pie crusts out on a floured surface, and then place it in a greased pie pan covered with parchment paper.
Refrigerate or freeze the other disk of dough.
For the Filling:
Preheat your oven to 425˚F.
Layer the bottom of the tart with tomatoes and green peppers.
Drizzle with olive oil.
Season with salt and pepper, but don't use too much salt because feta cheese is salty.
Sprinkle the crumbled feta cheese across the top.
Put it in the oven and bake for 20 minutes.
Reduce oven temperature to 375˚F and bake for an additional 15 minutes.
Allow to cool for 10 to 15 minutes before cutting and serving.