Boil a quart or more of milk separately with a couple of bay-leaves; rub the onion with the cold potatoes through a wire sieve and add it to the milk.

You can moisten the potatoes in the sieve with the milk.

When you have rubbed enough to make the soup thick enough, let it boil up and add to every quart a saltspoonful of thyme and a brimming teaspoonful of chopped blanched parsley.

This soup should be rather thicker than most thick soups.
When new potatoes first come into season, and especially when you have new potatoes from your own garden, it will often be found that mixed with the ordinary ones there are many potatoes no bigger than a toy marble, and which are too small to be boiled and sent to table as an ordinary dish of new potatoes.

Reserve all these little dwarf potatoes, wash them, and throw them for five or ten minutes into boiling water, drain them off and throw them into the potato soup whole.