Soak the peas overnight. Next day simmer in a quart (1 l.) of water with a teaspoonful of salt until tender. Put them through a moulin or liquidizer with their liquid. Lightly brown the sliced onions and the small onions separately and add to the peas. Season, and simmer till the onions are quite tender, 30 to 40 minutes.
Fry the slices of bread slightly in butter and float one on each bowl when serving.