Pesto spaghetti squash

1 medium spaghetti squash {approx 1- 1 1/2 lbs}3 Tb pesto1 Tb chopped onionSalt and pepperSprinkling of mozzarella or Parmesan cheeseCarefully cut squash in half, lengthwise, and remove all seeds. Smells like raw pumpkin - yum! Place open sides up, on a baking sheet. Sprinkle with salt, pepper and onion. {I used 1 Tb onion flakes.}Bake for 1 hour at 425 degrees. The meat of the squash will be soft when poked with a fork; like you're testing potatoes! Let cool for 5- 10 minutes so they will be easier to handle. Drag a fork through the squash to bring out the 'noodles.' Scoop into a medium bowl; combine with pesto. Spoon filling back into shells and sprinkle with cheese. Bake for 10-15 minutes longer till warm throughout and cheese is melted. Prep in advance is easy: Complete steps 1-4. Store in air tight containers or covered with plastic wrap 1-2 days. Sprinkle with cheese and bake just before serving.Use as a complete pasta substitute - add marinara and extra cheese! Re-using the shells as serving dishes makes for a festive touch at the holiday dinner table.