Preheat the oven to 400 degrees. Line a large baking sheet with parchment paper or aluminum foil.

Cut the spaghetti squash crosswise into 1-inch-thick rounds (this doesn't have to be precise; somewhere close 1-inch-thick is ideal). Note: If your squash is too hard to cut, pierce the exterior all over with a fork and transfer the squash to a microwave-safe plate. Microwave on high for 60 seconds, or until the exterior is slightly softened and easier to cut.

Once sliced into rings, use a spoon to remove the seeds and associated "strings" attached to the seeds (as if carving a pumpkin).

Arrange the rings on the prepared pan and brush the top lightly with olive oil. Season with a light sprinkling of salt and black pepper. Roast for 30 to 40 minutes, until the flesh is fork-tender (the skin might still be quite firm and that’s OK). Timing will depend on the size of your squash.

Remove the pan from the oven and cover it with aluminum foil for 5 minutes; this allows the squash to steam.

When cool enough to handle, use a fork to pull strands of squash from the skin. Serve as desired.