You press the not yet baked bread roll dough flat and coat it with the cream cheese.
(Of course you can also use homemade dough or ready-made pizza dough, the ready-made rolls are only very practical because they are exactly the right portion for parties)
Then you cut the onions into rings or pieces and cover the coated rolls with them, then you add the diced ham and bake the whole thing in the oven at 200 degrees for about 20 minutes.