For the dough: in a bowl, dissolve the yeast with a small amount of warm water, add the egg yolks, salt, oil, melted butter and flour. Mix all the ingredients well and beat vigorously until a ball of elastic dough forms. Cover the dough and place it in the refrigerator and let it rest until it doubles in size.
Cut the meat into very thin cubes and wrap them in the dough.
Preheat the oven to 180º C.
Line a rectangular shape with parchment paper or bar with butter and fill with flour. Pour the batter and brush the surface with a beaten egg yolk with a little olive oil.
Bake at 180ºC, for about 40 to 50 minutes. Let cool and serve.