- Cook the spaghetti squash in a pan of water for about 1 hour and 15 minutes.
- Preheat oven to 180 degrees. Bake the bacon on the grill for about 15 minutes. Remove from the oven and place on paper towels to absorb excess fat. Cut into pieces.
- When the squash is almost cooked, fry the chopped onion in a little oil in a frying pan, add the crème fraîche and leave to reduce for about ten minutes, stirring regularly.
- Remove from the heat, add the beaten egg yolk and mix vigorously. Season with salt and pepper.
- Cut the squash in half, remove the seeds and scrape out the flesh with a fork.
- Serve the plates: first the spaghetti squash, then the sauce, decorate with bacon bits and finish with the grated Gruyère cheese.
Tip: When cooking the bacon, place baking paper on the baking sheet, about 10 cm below your rack, to catch the fat and avoid dirtying your oven.