If you are using ground beef, add it to the mushrooms and onions. Add a sprinkle of salt and pepper. Use a spatula to break it up and cook until the ground beef over medium heat until it is browned (about 10 minutes).
Sprinkle two tablespoons of flour over the mixture.
Use a spatula to mix the flour into the meat and cook it over medium low heat for two or three minutes.
Add a cup of milk or cream and salt and pepper.
Let the mixture cook over medium heat until it bubbles and thickens.
Turn the heat down to low and add ¼ of sour cream. Mix in the sour cream and let the mixture heat through. Do not let it boil. Taste it and decide whether you want to add more sour cream. If so, I recommend adding one tablespoon at a time.
If the mixture is too thick, add more milk or cream until it reaches the desired consistency..
Mix in two tablespoons of fresh, chopped parsley. Taste and add salt and pepper as needed.
Place a portion of the roasted spaghetti squash on each plate. Top with the stroganoff sauce and some fresh parsley.
Recipe by Pinot & Pie at https://pinotandpie.com/roasted-spaghetti-squash-stroganoff-beef-or-vegetarian/