From America's Test Kitchen Season 7: Best Beef Stew
Cooked properly, acorn squash develops a sweet, almost nutty flavor and moist, smooth flesh—a result that should not take hours. But after what seems like eons in the oven, acorn squash often lands on the table with little flavor and a mealy, stringy texture. We wanted the flavor of better, slow-roasted acorn squash in a fraction of the time. To our astonishment, microwaving was the ideal cooking method, presenting a squash that was tender and silky smooth, with nary a trace of dryness or stringiness. Microwaved on high power for 20 minutes, the squash was perfectly cooked. It was best to halve and seed the squash before cooking; whole pierced squash cooked unevenly. Last, we learned that when added before cooking, salt seemed to better permeate the squash. Filling in the only remaining gap, equal portions of butter and dark brown sugar gave the squash ample, but not excessive, sweetness. And for a smooth, cohesive filling mixture, combining the butter and sugar with a pinch of salt and briefly broiling the final product eliminated the nagging sticky glaze problem. Finishing the squash under the broiler also gave it a welcome roasted texture and great caramelized flavor.
Squash smaller than 1 1/2 pounds will likely cook a little faster than the recipe indicates, so begin checking for doneness a few minutes early. Conversely, larger squash will take slightly longer to cook. However, keep in mind that the cooking time is largely dependent on the microwave. If microwaving the squash in Pyrex, the manufacturer recommends adding water to the dish (or bowl) prior to cooking. To avoid a steam burn when uncovering the cooked squash, peel back the plastic wrap very carefully, starting from the side that is farthest away from you.