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ONIONS (au Gratin)
Slice some Spanish onions into a fireproof baking-dish, well-greased; add a layer of crumbs and a little pepper and salt, then another layer of onions, and so on until the dish is full. Place some dabs of butter on top, and cook in the oven for about an hour and a half, or until the onions are quite soft and brown. Grate some cheese over, return to the oven for a few minutes, and serve.
A straightforward gratin that depends almost entirely on giving the onions long enough to collapse and sweeten. The original omits quantities and temperature, so both need filling in.
- Oven temperatureNo setting is given; an hour and a half of slow collapse points to a moderate oven, 325-350F. Higher and the crumbs on top scorch long before the onions in the middle are soft.
- Spanish onionsThe large, mild, straw-skinned kind, still sold under that name. Two or three large ones fill a 9-inch dish. Ordinary yellow onions work but are sharper; sweet varieties such as Vidalia are closest in spirit.
- Slice thicknessAim for about 1/8 inch. Thick slabs will still be firm at the ninety-minute mark, and the dish gives no liquid to help them along.
- CrumbsDry white breadcrumbs, not the sandy commercial sort and not panko. Their job is to absorb the onion juices into something creamy, so they should be fine and plentiful between the layers.
- Cover, then uncoverThe recipe cooks the dish open throughout, but the onions release a good deal of water and will steam themselves soft under foil for the first hour, then finish uncovered to brown, if the top looks like drying out.
- The cheeseAdded only at the end, for a few minutes, so it melts rather than hardens. A dry Cheddar or Gruyere grates and browns better than anything soft.
- ButterBe generous with the dabs on top and consider dotting the middle layers too. Onions and dry crumbs alone make for a mealy dish.
- YieldServes four as a side, two as a supper dish with bread. It reheats well and is arguably better the next day.
Gratin here means a dish finished with a browned crust; the word is generally traced to gratter, to scrape, after the crisp scrapings from the bottom of the pan. Cassell's New Dictionary of Cookery ran to thousands of entries arranged alphabetically, and the onion section is characteristically long. Spanish onions in particular were an import valued for mildness and size, and English cookery books of the period treat them as a vegetable in their own right rather than mere seasoning, stuffing them, baking them whole or layering them like this. The reliance on breadcrumbs and a scattering of cheese rather than a cream sauce marks this as a plain family version of the gratin rather than a restaurant one.