Dissolve yeast in 1/2 cup warm water with 1 tsp sugar and let sit for 5 minutes.

In a food processor, combine flour, margarine, yeast mixture, 7/8 cup shredded cheese, salt, and pepper.

Process until a smooth ball forms, adding sour cream as needed to bring the dough together.

Let the dough rest in a warm, dark place for 1 hour.

Preheat oven to 375F (190C).

On parchment paper, roll out the dough to about 1/4 inch thickness.

Cut the dough into 3-4 inch long by 1/2 inch wide sticks.

Lightly beat the egg yolk and brush it on top of the sticks.

Sprinkle the remaining 2 7/8 tablespoons of shredded cheese on top.

Let the sticks rest for 10 minutes.

Slide the parchment paper with the cheese sticks onto a cookie sheet.

Bake for 20-25 minutes, or until the cheese is golden brown.