To prepare Oil Pastry for Single-Crust Pie: In a bowl stir, together flour and salt. Combine milk and cooking oil. Add milk mixture all at once to flour mixture. Stir with a fork until dough forms; form into a ball. On a lightly floured surface slightly flatten dough. Roll dough into a 12-inch circle. Ease pastry into a 9-inch pie plate. Trim pastry to ½ inch beyond edge of plate. Fold under extra pastry; crimp edge as desired. Prick bottom and sides of pastry generously with the tines of a fork. Bake in a 450°F oven for 10 to 12 minutes or until pastry is golden. Cool on a wire rack.
To prepare the filling: Place 1 cup of the strawberries and the water in a food processor bowl. Cover; process until smooth. Transfer to a small saucepan. Bring to boiling; simmer 2 minutes.
In a medium saucepan stir together sugar and cornstarch; stir in berry mixture. Cook and stir over medium heat until bubbly. Cook and stir for 2 minutes more. Remove from heat; stir in enough red food coloring to tint a rich red color. Cool to room temperature.
Fold remaining strawberries into cooled mixture; pour into pastry shell. Cover with plastic wrap or foil; chill for 3 to 4 hours. If desired, serve with whipped topping.