01 - Preheat oven to 400°F. Line a baking sheet with parchment paper.
02 - Carefully halve the spaghetti squash lengthwise and scoop out the seeds. Drizzle cut sides with 1 tbsp olive oil and sprinkle with salt and pepper.
03 - Place squash halves cut-side down on the baking sheet. Roast for 35–40 minutes, or until flesh is tender and easily shredded with a fork.
04 - Meanwhile, heat 1 tbsp olive oil in a large skillet over medium heat. Add shallot and garlic; sauté for 2–3 minutes until fragrant.
05 - Add baby spinach and cook, stirring, until wilted (about 2 minutes). Remove from heat.
06 - When squash is cool enough to handle, use a fork to scrape the flesh into spaghetti-like strands.
07 - Add the squash strands to the skillet with the spinach mixture. Crumble in the Boursin cheese and toss until the cheese is melted and everything is well combined.
08 - Taste and adjust seasoning with extra salt, pepper, or red pepper flakes if desired. Transfer to a serving dish. Sprinkle with grated Parmesan before serving.