On Food and Cooking

Stir-Frying and Sweating Two important
variations on frying exploit opposite ends of
the temperature scale. One is high-
temperature stir-frying. The vegetables are cut
into pieces sufficiently small that they heat
through in about a minute, and they’re cooked
on a smoking-hot metal surface with just
enough oil to lubricate them, and with
constant stirring to ensure even heating and
prevent burning. In stir-frying it’s important
to preheat the pan alone and add the oil just a
few seconds before the vegetables; otherwise
the high heat will damage the oil and make it
unpalatable, viscous, and sticky. The rapidity
of stir-frying makes it a good method for
retaining pigments and nutrients. At the other
extreme is a technique sometimes called
“sweating” (Italian soffrito or Catalan
soffregit, both meaning “underfrying”): the
very slow cooking over low heat of finely
chopped vegetables coated with oil, to
develop a flavor base for a dish featuring