Preheat your oven to 400°F and line a large baking sheet with parchment paper.
Carefully slice the spaghetti squash in half lengthwise, scoop out the seeds, and brush the flesh with a small amount of the olive oil and a pinch of sea salt.
Place the squash halves cut-side down on the baking sheet and roast for 40-45 minutes until the skin is easily pierced with a fork.
While the squash is roasting, peel and devein the shrimp, then pat them completely dry with a paper towel.
Use a fork to scrape the roasted squash flesh into long, spaghetti-like strands and set them aside in a warm bowl.
Heat the remaining olive oil in a large skillet over medium-high heat.
Add the minced garlic and red pepper flakes to the skillet, sautéing for about 60 seconds until the aroma is released and the garlic is golden.
Add the shrimp to the pan in a single layer and cook for 2-3 minutes per side until they turn pink and opaque.
Stir in the lemon juice, sea salt, and black pepper, tossing the shrimp to coat them thoroughly in the sauce.
Divide the spaghetti squash strands between plates, top with the garlic shrimp, and garnish with fresh parsley and grated parmesan cheese.