Mix flour, baking powder and salt in a bowl. Add oil and milk and make a dough. Use a rolling pin to roll out the dough. Spread the ketchup on the rolled out base and add ham and cheese.
Roll the pizza as a swizz roll and cut into aprox. 20 slices. Put the slices on a oven tray covered in grease proof paper. Bake for 20 minutes in 200º.
For more flavour replace the ketchup with a batch tomato sauce and add chilli powder and paprika to taste.