Boil the onions in slightly salted boiling water and rub them through a sieve. Brown 2 oz (50 grn) sugar. Bring 1 cup of the onion water to a boil, trickle, stirring, one more cup of the onion water shaken with the flour into it. When it boils and thickens, add 2 oz (50 gm) of butter, browned sugar, the juice from 1 lemon, and onions. Salt,  some sugar, and heat without bringing to a boil.