Place flour, butter & salt into a large bowl. Rub butter into flour with fingertips to resemble FINE breadcrumbs. (work quickly before butter becomes soft).
Add water to mixture using a COLD knife, stir until dough binds together. Add more water (teaspoon at a time) if dough seems to dry.
Wrap dough in plastic wrap and chill 15 to 30 minutes.
For Filling :
1 1/2 pounds Damson Plums.
4 oz sugar.
Half fill large baking bowl with plums. Sprinkle with sugar. Put rest of plums on top making higher in center.
Roll or pat out chilled pastry dough larger than circumference of baking bowl. Trim to fit bowl. Press dough around bowl to seal in juices. Use remaining dough to make a trim to go around bowl and place over the dough covering the fruit. Cut several vent holes in top of dough.
Brush lightly with water. Sprinkle sugar on top of pastry.
Bake at 400 degree F. in preheated oven for approximately 1 hour.