Tart Dough: Use 1/3 cup of butter for every 1 3/4 cups of flour. Rub the butter into the flour until it resembles “crumbs” Add 1/2 teaspoon salt. Ever so carefully add cold water, gathering the mixture together. The dough should be dryer than a samosa dough. It should just stick together. Work on a cool work surface and always use cold water for tart dough. Don’t handle tart dough too much. Best tarts are “rolled” without a rolling pin – using one’s hands to press the dough into the tray. You may roll bits of dough to fit your tart tins or roll all the dough out and cut circles that fit your tray. A bit less than 2 cups of flour makes 12 medium tarts. (I use a muffin pan which makes 3"diameter muffins)
Once the trays are lined with tart dough prick the base of the tarts with a fork a few times.
Bake in a pre-heated oven (medium high/heat for about 8-10 minutes. Fill the tarts and continue to bake for another 8-10 minutes.

More butter may be used for a flakier, richer tart dough but for health purposes the above quantity is fine.

Sweet Tart Dough: Add 2 Tablespoons of sugar instead of salt.