Combine flour, sugar in salt in a bowl
Cut butter into flour until you get pea-sized crumbles
Gradually add water, mixing with a fork until the dough comes together
Knead until smooth, 5 - 10 minutes
Divide into 30 equal sized pieces
Roll each piece into a circle approximately 4" - 6"
Fill each circle with approximately 1/4 cup of pork filling
Close empanada and prick the top 3-4 times with a fork
Using a dough or pizza cutter, trim the edges to an even rounded cut
Using your fingers, seal the edges of the dough and roll the edges slightly
Using a fork, crimp the edges all the way around the sealed side
Brush with egg yolk
Place empanandas on a baking sheet in the pre-heated oven until golden brown, about 25 minutes.