Piroshki - cooking recipe

Ingredients

1 (10 oz.) pkg. frozen puff pastry shells
2 Tbsp. butter
1/4 c. finely chopped onion
3 Tbsp. sour cream
1 1/2 c. chopped cooked beef shank meat
1/2 tsp. dried dill
salt and pepper to taste
1 egg yolk, beaten with 1 Tbsp. water

Preparation

Remove pastry shells from package and let stand at room temperature to thaw 30 minutes.