1. In a large mixing bowl, place the yeast, sugar, and half the milk. Allow to stand for 5 minutes, or until the mixture is foamy. Beat in the remaining milk, egg, egg yolk, sour cream & butter.

2. In another bowl, sift together the flour, cornmeal & salt. With an electric mixer set on low, gradually beat the flour mixture into the egg and milk mixture until the dough is smooth and elastic.

3. Form the dough into a ball. Transfer to an oiled bowl, and turn to coat with the oil. Cover and let rise in a warm place for 1 hours. Punch down.

4. Preheat oven to 450F / 230C / Gas Mark 8.

5. Divide the dough into 24 pieces and shape into balls. Keep dough covered with a damp cloth.

6. On a lightly floured surface, roll each piece of dough into a 4" (10cm) round. Use a cookie cutter to trim the edges.

7. Place filling on bottom 2/3 of round & fold rounds in half, enclosing the filling. Seal the edges of the dough and crimp decoratively.

8. Transfer the empanadas with a spatula to a lightly oiled backing sheet and bake them in the middle of the oven for 10-15 minutes, or until golden. Transfer to a cooling rack and cool before serving.