To make Myrna’s crust:

3 cups flour
1 teaspoon salt
1 teaspoon sugar
8 tablespoons unsalted butter, cut up and chilled
8 tablespoons shortening, scored and frozen (See description below)
About ½ cup water
1 ice cube
2 teaspoons red wine vinegar

For the filling:

6 – 8 cups cut up rhubarb, ½ inch sections (depending on the size of your pie pan
1 pint raspberries
¾  cup sugar
3 tablespoons corn starch
1 teaspoon vanilla extract
1 ½ tablespoons unsalted butter

Milk or cream for brushing
Sugar for sprinkling

Instructions
Makes 1 9-inch pie

To make the crust, cut the butter into small cubes and refrigerate. Spread the shortening on a piece of foil about ¼ inch thick and score it with a table knife to make a grid of lines, then freeze it. This will form cubes of shortening, once chilled and hardened. Place an ice cube in a one cup measure and add enough water to bring it up to ½ a cup then add the vinegar to this and set aside to chill and melt.

In a mixer with a paddle attachment, place the flour, salt, sugar, chilled cut up butter and frozen shortening (bend the foil back to cause the shortening to release from the foil) and mix on low till the fat pieces are the size of large peas. Add the ice water/vinegar and turn the mixer on and count to 25 then turn the mixer off. Form the dough into 2 disks and chill over night or at least 2 hours.

On a floured surface with a rolling pin, roll out one piece of dough and line a 9 inch pie pan with it, gently easing the dough into the corners of the pie pan, leaving the edges overhanging. Chill it while you roll the second piece out, then let it rest on a parchment or wax paper lined sheet pan, in the while you make the filling.

For the filling in a large bowl, place all the ingredients except the butter and toss or fold them together to mix. Pour it into the bottom crust, even it out a bit and dot with the butter. Brush the edge of the bottom crust with water and then lay the top crust over the filling. Pinch the two layers together, trim it and crimp as you wish. Brush the top of the crust with milk, sprinkle it with sugar and cut 6 slits in the top for vetting, to help it release it’s steam without bursting during baking.

Bake at 400 degrees for 60-70 minutes till the top crust is golden brown and a few clear juices are bubbling out of one of or more of the vent slits. Let cool and serve in wedges for dessert.