In a medium bowl, lightly stir the flour and salt together with a fork. With two knives or a pastry blender, cut in the shortening until the mixture resembles coarse crumbs.

Add in a little cold water (a tbsp. at a time), mixing with a fork to make the pastry just hold together. Use your hands to shape the pastry into a ball.

Lightly flour your board or counter and roll out the pastry to 1/8 inch thickness. Use rolling pin to transfer pastry to pie pan and gently ease it into the pan so as to not tear the crust. Press the crust up the sides of the pan and crimp the edges, tucking excess under and making a decorative edge as desired or trimming the excess.

Preheat oven to 350 degrees.

In a medium or large bowl, whisk eggs very well. Beat in corn syrup, sugar, margarine and vanilla and make sure all ingredients are well-combined.

Arrange the pecan halves in a single layer in the bottom of the piecrust in a circular, coil-like fashion, covering as much of the bottom of the pan as possible.

Pour the egg mixture over the pecans slowly, trying not to move the pecans around.

Bake for 1 hour. Cool on wire rack for at least 45 minutes before serving. Serve with fresh whipped cream or vanilla ice cream.