Put flour and salt in the bowl of a food processor. Cut the butter, and shortening into the flour. Process a few seconds until the mixture resembles a coarse meal. Drop by drop add the water, processing briefly. The whole process should take about 20 to 30 seconds. Wrap and chill for an hour. Remove from refrigerator, and let stand 15 minutes before rolling. (The Martha Stewart Cookbook.) You can double this up for a top and bottom crust.
In a medium sized sauce pan combine sugar, cornstarch, and 7-UP until creamy. Cook over a medium to a medium high heat until the mixture becomes thick. When this mixture becomes thick, cool to room temperature, and add a couple of drops of red food coloring. Wash, and cut strawberries into quaters, or smaller depending on how large they are. Sprinkle a teaspoon or two of sugar on the strawberries, and place them into the shell. Pour the cooled 7-Up mixture over the strawberries. Allow this to set for a few minutes. Serve with plenty of Whipped Cream.