Sauce (Tablespoons flour cup brown)

A three-ingredient sweet sauce of the sort that was ladled over steamed puddings, cottage pudding or plain cake. It comes together in about five minutes, and nearly everything that can go wrong with it is a lump.

• Mix the flour with the sugar dry"Mix well" is all the original offers, but the safest reading is to combine the flour and brown sugar thoroughly before any water goes in, then whisk the water in gradually. Flour dropped into hot liquid will seize into lumps that never fully dissolve.
• Boil it longer than it looks like it needsThe sauce thickens well before the flour is cooked. Keep it at a gentle boil, whisking, for three to five minutes after it coats the spoon, or it will taste pasty.
• "Flavor" means an extract or spiceThe original assumes the cook knows what her family likes. About a teaspoon of vanilla, or lemon extract, or a grating of nutmeg, stirred in off the heat so the volatiles do not boil away.
• Butter is the usual unwritten additionButter is a common unwritten addition -- many period pudding sauces of this type were finished with a tablespoon or two of butter beaten in at the end. It is not called for here, but it smooths the texture considerably.
• Brown sugar has changedBrown sugar -- the recipe does not specify a grade. Light brown sugar gives a mild caramel note; dark brown or muscovado is likely to dominate whatever you flavor it with.
• Yield and consistencyMakes roughly a cup and a half, enough for four to six servings. It thickens further as it cools; if it sets too stiff, thin with a spoonful of hot water rather than reheating hard.