For the pizza buns, crumble the yeast into a bowl and sprinkle with a little sugar. Add water and milk. Add oil, salt and flour. Roll out the dough to a thickness of about 1 cm. Spread with ketchup.
Cover with ham and bacon and sprinkle with oregano. Roll up and cut into 1 cm thick slices. Place them on a baking sheet and sprinkle with cheese.
Bake the pizza buns in the oven at 170°C for about 20-25 minutes.