Spring Soup
1 quart White Stock I or II 1 large onion thinly sliced 3 tablespoons butter 1/2 cup stale baker's bread 1 cup milk 1 cup cream 2 tablespoons flour Salt and pepper Cook onion fifteen minutes in one tablespoon butter; add to stock, with bread broken in pieces. Simmer one hour; rub through sieve. Add milk, and bind with remaining butter and flour cooked together; add cream, and season.
A white onion cream thickened the old way, with bread rather than potato or extra flour. The whole character of the soup depends on keeping the onion pale.
- Keep the onion whiteThe fifteen minutes in butter is a sweating, not a browning. Use low heat and a lid; any colour on the onion turns the finished soup grey-beige and gives it a caramelised note the recipe does not want.
- White stockThe book's White Stock I or II is a pale veal or veal-and-chicken stock, not browned. A good low-sodium chicken stock stands in; avoid dark or roasted-bone stocks.
- Stale baker's breadA plain white loaf from a bakery, gone stale, torn into pieces -- not a flavouring so much as the thickener. Half a cup loosely packed is roughly 1 oz. Skip sourdough and anything seeded or heavily flavoured.
- Rubbing through a sieveA blender or stick blender does this in seconds, though a pass through a fine sieve afterwards is still worth the trouble for a properly smooth texture.
- The butter and flourTwo tablespoons each of butter and flour cooked together is a white roux: keep it on low heat two or three minutes to lose the raw-flour taste without colouring, then whisk in the hot soup gradually.
- Add the cream last, off the boilOnce the cream is in, hold the soup below a simmer. Boiling a cream soup bound with flour can make it separate and dulls the fresh dairy flavour.
- SeasoningThe recipe leaves salt and pepper to the end, so season after the cream and taste again once it is properly hot. White pepper keeps the appearance clean.
- YieldAround 5 to 6 cups depending on how much reduces during the hour's simmer; four to six first-course servings.