The first set were useful because of the lids. I have a couple of pudding basins which are both pyrex - really good for making this as you can check that the juice has got all the way through.

To us a mixing bowl usually means a bigger one, although we would use the small ones for mixing small amounts. So a small mixing bowl is probably exactly the same thing, and would work perfectly. It is just to make it the right shape to turn out easily.

And a standard saucer just fits into the top of a bowl this size to put even weight onto the bread and fruit mixture - it doesn't work if you don't put enough weight on.