Step 1Preheat the oven to 200 °C/ 400 °F (fan assisted), or 220 °C/ 425 °F (conventional). Cut the spaghetti squash in half, either lengthwise or widthwise (if you cut it widthwise, you'll get slightly longer strands once it's cooked). The skin of uncooked spaghetti squash is hard and it's difficult to cut through. Use the tip of a chef's knife to break through the skin in the middle part and push the blade down until cut through. Using a spoon, scoop out the seeds.