Add berries, sugar and lemon juice to a large saucepan over medium heat.

Simmer until warm and juicy, about 5-10 minutes, gently stirring occasionally.

Spoon out about ½ cup of the juice from the pan into a bowl. Stir cornstarch into the juice until smooth.

Bring pot of berries back to a simmer and slowly pour in the cornstarch. Gently stir mixture until thickened, about 2-5 minutes.

Remove from heat and stir in the butter. Allow to cool for 15 minutes.

Pour mixture into unbaked pie shell (in a 9 in deep dish pan).

Add lattice top or a whole top with holes pricked on top for steam to escape.

Pinch the edges of the top and bottom pie crusts together and crimp the edge, if desired.

Brush a thin layer of beaten egg white over the top of the pie and sprinkle lightly with sugar.

Bake at 400 degrees F for 40-45 minutes. Check after about 25 minutes and place a piece of tinfoil over it if the top crust is getting too brown.

Remove to a wire cooling rack and allow to cool for several hours.

Once cooled completely, you can cut into it or cover it and refrigerate it overnight to serve the next day.

Roll out your crust on a lightly floured counter or on a piece of parchment paper.

Use a pizza cutter to cut strips of dough.

Lay your longest strip across the middle of the pie then lay a few shorter strips on either side, parallel to each other and spaced evenly.

Fold back the second and fourth strip and lay a shorter strip of dough perpendicular to other dough strips. Unfold those dough strips over the new strip.

Fold back the first, third and fifth strips in the same direction and lay another dough strip across the pie. Unfold the first, third and fifth strips over the new strip.

Repeat until pie is covered with a lattice crust.

If dough strips hang over the edge of the pie, trim them to the edge.

Pinch the lattice top with the bottom crust to form one unified outer edge.

Crimp the edges.