Preheat oven to 400 degrees.
Cut Spaghetti Squash in half lengthwise and scoop out seeds. Place flesh side down on large rimmed baking sheet. Pour a little water in bottom of pan to keep moist.
Cook 30-35 minutes until it can easily be pierced with a fork. Remove from oven and flip squash over. Allow to cool about 10-15 minutes.
Remove spaghetti squash strands with a fork in place in large bowl. I like to then drizzle with 1 tbsp. olive oil and stir.
Meanwhile for sauce add 2 tbsp. olive oil to large sauce pan with red chili pepper flakes over medium heat for about 1 minute.
Then add onions, carrots, celery, & garlic and cook about 2-3 minutes till translucent.
Add mushrooms, walnuts, & seasonings and cook another 10 minutes.
Finally add canned tomatoes, half & half cream & wine and cook about 20-30 more minutes.
Spoon over cooked spaghetti squash.
Optional toppings include shredded parmesan cheese & parsley.