Gravy
To each cup of liquid add, gradually, 2 tablespoons flour mixed till smooth, with an equal quantity of cold water. Cook as white sauce. Strain.
A bare-bones proportion rather than a recipe, of the kind cookbooks of the period could print because every reader already knew the method. Two points carry the whole thing: the ratio, and what "cook as white sauce" meant to the original audience.
- The ratio2 tablespoons flour per cup of liquid is the standard "medium" proportion of the period white sauce tables, roughly pouring consistency. Cut to 1 tablespoon per cup for a thin pan gravy to pass at table, or go to 3 for something closer to a sauce for croquettes.
- What "liquid" meansThe recipe says only "liquid"; for a gravy that would normally mean the drippings and browned sediment from the roasting pan, loosened with stock, milk or water. Pour off most of the fat first and leave the dark sediment; that sediment is where the flavor is.
- "Cook as white sauce"A cross-reference to the book's white sauce method: the thickening is cooked into the hot liquid with constant stirring until it thickens and no longer tastes of raw flour. Let it bubble a little rather than sit at a bare simmer; under-cooked flour gravy is pasty and chalky.
- Slurry, not rouxMixing flour with cold water and stirring it into hot liquid is the quickest route and does not brown the flour at all, so the color comes entirely from the drippings. If you want a deeper flavor, cook the flour in the reserved fat until it smells nutty and add the liquid to that instead.
- Lumps and the strainerThe instruction to strain is not decorative. A water slurry poured into hot liquid lumps easily, and straining through a fine sieve is faster than whisking the lumps out.
- SeasoningNo salt or pepper is specified, presumably because seasoned pan juices were expected to supply it. Taste at the end; pan juices vary enormously in saltiness.
- YieldThe recipe gives no yield, only a proportion. As a rough working figure, a cup of finished gravy will do for about four at a roast dinner; scale the proportion to the pan liquid you have.
The Metropolitan Cook Book was one of the great free-distribution cookbooks of the twentieth century, handed out by Metropolitan Life Insurance agents to policyholders as a goodwill item and reprinted in enormous numbers over several decades. That purpose explains the compression here: the book was aimed at ordinary housekeepers cooking economically, and it repeatedly builds recipes out of a handful of master methods rather than repeating them. "Cook as white sauce" is a cross-reference to the sort of white sauce table many American cookbooks of the era printed, in which the same liquid is thickened in thin, medium and thick proportions and then made to serve for creamed vegetables, croquettes, chowders, souffles and, as here, gravy. Thrift runs through the book as well, and the habit of using what the pan gives you; nothing from a roast was meant to be poured down the sink.