Microwave can never replace the traditional oven, but it's what they don't do -- cook with dry heat -- that makes them useful. For example, take the notoriously hard-to-peel butternut squash -- you can literally lose a finger slicing the skin off of one and cutting it into cubes. But the microwave, with its water-molecule-moving radio waves, makes short work of peeling and softens the flesh almost imperceptibly but enough to make dicing the squash into cubes effortless. You can cook a whole squash all the way through in a microwave too, in a little less time than it takes in an oven.
Microwave the Peel Away
Skinning an uncooked butternut squash is like trying to peel the bark from an oak tree with a paring knife -- tedious and tiresome. And butternut squash laughs in the face of peelers, so save them for the soft-skinned veggies. Like most cold-hardy vegetables, butternut squash has a tough epidermis that protects its flesh and seeds from the elements -- and tries your patience when prepping. But the microwave changes that; as the water molecules beneath the skin agitate and steam, it loosens from the underlying flesh, making peeling a breeze. To microwave a whole squash for peeling, slice off about 1/4 inch from the top and bottom, and score the skin 20 or 30 times using a fork. Next, microwave on high for 3 1/2 to 4 minutes. Peel the squash using a peeler or paring knife when it's cool enough to handle.
Microwaving Whole Squash
Thanks to their tough skin and the microwave's efficiency at creating steam in semi-permeable containers, butternuts develop buttery-soft flesh perfect for scooping and pureeing after a few minutes in the microwave. You don't need to dice the butternut squash first. Just nuke it in two segments, the bulbous portion containing the seed cavity and the neck, to compensate for their different cooking times. Cut about 1/4 inch from the ends of the squash, and slice it in half crosswise at the bottom of the neck. Next, poke holes through the skin all over, and microwave each segment in a microwave-safe dish with about an inch of water in the bottom until tender. Although cooking times vary with the size of the squash, expect the neck to take about 12 to 15 minutes and the bottom to take about 10 to 12 minutes.
Cubing a Squash
Cubing and par cooking a squash is the first step before freezing. After cubing and par cooking, you can mash the squash and store it in ice-cube trays, pack it into freezer-safe containers or finish cooking the squash in the microwave. Slice the squash in half lengthwise and scoop out the seeds. Microwave the squash halves one at a time for 3 to 4 minutes, just long enough to soften the skin for peeling. Next, peel the squash and slice it crosswise into 1-inch slices. Then cut each slice into 1-inch cubes. Store the cubes up to two days in an airtight container in the fridge or up to six months in the freezer for best quality.
Microwaving Cubed Squash
You want squash cubes to stay as moist as possible during microwaving. To ensure this, place the cubes in a microwave-safe dish and add about 1/4 inch of water to the bottom. Cover the dish tightly with plastic wrap and and slice a few slits in it to let steam escape. Microwave the cubes on high for 6 to 7 minutes -- for up to 2 pounds of squash -- or until fork tender. Now you can serve the squash as is or mash it with a fork and store it in ice-cube trays for later use. If you store the squash in ice-cube trays, pack each tray in a heavy-duty freezer bag.