For concentrating and coaxing flavor from summer squash, the best cooking methods are 1) sautéing, 2) stir-frying, 3) grilling and 4) roasting. All do a great job of quickly zapping out water while leaving behind flavorfully browned, relatively firm pieces of squash.
Microwavingis a close second. It doesn’t require additional water and of course, cooks the squash very quickly, producing a surprisingly good result. It just can’t add the second element of browning to coax out additional flavor.
When cooking summer squash, keep in mind that it’s low on flavor, largely because it’s mostly water (up to 95 percent!) So cooking summer squash is all about working around and with its high water content. The first two Big Things to know about working with this watery vegetable are:
1) Concentratewhatever flavor there is within its water-logged flesh, and then
2) Coaxout that flavor even more with “flavor boosters.”
3) Large Amounts Required Summer squash loses a lot of volume when cooked, as all its water evaporates or dissipates, leaving behind a mere remnant of the starting vegetable. To end up with a worthwhile amount in a finished dish, you must start with an amount that seems overwhelming. So don’t be alarmed when a recipe calls for 2, 3 or even 4 pounds of squash. It will cook down by about half, in much the way as spinach, another water-filled vegetable.
Pattypan squash are the one exception to this general rule. As explained in “Making Heads and Tails of the Squash Kingdom,” patty pan’s flesh is much denser than other summer varieties, so it stays firmer and doesn’t lose as much volume when cooked. Accordingly, more normal-looking amounts can be used for this variety.