Pierce the spaghetti squash all over with a sharp knife, about 1/2-inch deep. Place the squash on a microwave-safe plate and microwave for 10 to 15 minutes, until the outside gives slightly when you press in, checking and turning every 4 to 5 minutes. Remove the squash from the microwave and let cool for 10 minutes.
When the squash is cool enough to handle, halve lengthwise, discard the seeds and scoop the flesh into a large bowl, being careful to keep the spaghetti-like strands intact.
Heat the broth in a large skillet over medium-high heat. When the broth comes to a simmer, reduce the heat to low and add the 1/4 cup half & half and 1/4 cup grated parmesan cheese. Simmer until the cheese melts. Fold in the squash and roasted red peppers. Season to taste with salt and pepper.
If you've grated extra parmesan cheese, serve it on the side to be sprinkled on top after dish is served (see photo above).
Serves 4 people.