Pre-heat oven to 200°C/390°F. Halve spaghetti squash lengthwise and remove the core with a spoon. Transfer squash to a parchment-lined baking sheet. Brush with olive oil and season with salt and pepper. Bake for approx. 40 min.
Wash endive, cut off the root and pick the leaves. Chop walnuts, and set aside. Chop mint. In a bowl mix grapefruit juice, cider vinegar, and linseed oil and season with pepper to taste.
Remove squash from oven, fray out the pulp with a fork, add to a large bowl and let cool down. Once cool, add mint, walnuts, dried cranberries, and pomegranate seeds and mix well.
Fill each endive leave with the squash mixture. Drizzle with grapefruit-dressing, season with salt and pepper to taste and enjoy!