Preheat oven to 400°F and line a sheet pan with parchment paper.
Cut the spaghetti squash in half lengthwise with a sharp knife; if too hard to cut, microwave the whole squash for 2 minutes to soften slightly.
Scoop out the seeds and stringy bits with a spoon.
Drizzle cut sides with olive oil and season with half the salt and all the pepper.
Place squash halves cut-side down on the prepared sheet pan.
Roast for 40 minutes, until the flesh is fork-tender and edges are lightly caramelized.
Remove from oven and cool completely on the counter for at least 30 minutes before handling or sealing.
Use a fork to scrape the flesh into long strands, working from the edges toward the center.
Transfer strands to a large bowl and toss with the remaining salt.
Let the salted strands sit for 10 minutes to release moisture, then drain off any liquid that collects at the bottom.
Portion drained strands into 5 glass meal prep containers.
Label each container with today’s date on the lid.
Refrigerate and use within 5 days, or freeze for longer storage.