To cook a spaghetti squash in the microwave, cut it lengthwise, and remove the seeds. Place half of it in a microwavable dish with a lid, and pour a little water in the hollow of the squash. Place the other half and the lid on top, and microwave it for 10 minutes on full power. To microwave the whole spaghetti squash without cutting first, cook it on high for five minutes, adding two-minute increments until a fork pierces it easily.
Spaghetti squash are hard and sometimes difficult to cut. Use a sharp kitchen knife carefully to avoid injury. When cutting the squash before cooking, use a spoon or fork to scrape out the seeds and loose fibers in the middle.
Adding water to the middle of the cut squash helps steam the vegetable as it cooks in the microwave. Put the first half in the dish with the cut side up, and if it doesn't rest evenly in the dish, cut a small slide from the rounded outside to keep it steady. The top half should line up with the bottom half. Lift the dish into the microwave carefully so that the squash doesn't shift.
When microwaving a whole spaghetti squash, cut it in half lengthwise after it is done cooking, doing so with caution to avoid burns. Then, scrape out the seeds and fibers.
Scrape the inside of the spaghetti squash with a fork to separate the strands. Scoop them out of the squash to finish the process.