Preheat oven to 400 degrees F
Prepare spaghetti squash:
Clean the outside of squash with warm water and pat dry
Cut squash in half, lengthwise and pull off the stem
Scoop out seeds, you can throw them away or clean, dry and bake them
Pour a dash of olive oil into each half and rub surface with oil, using your hands or a brush
Cut one piece of garlic in half and rub it all over the oiled surface of the squash and season generously with salt and pepper
Place both halves of the squash face down on a foiled baking sheet and bake for 40 minutes
Meanwhile, mince remaining two cloves of garlic
Dice yellow onion
Drain can of tomatoes
When there are about 10 minutes remaining on timer for squash, heat 1/2 tablespoon olive oil on medium heat in a frying pan
Add garlic and cook until fragrant before adding diced onions, cooking until translucent, turn element down to low-medium
When the squash is done, let it rest for about five minutes, face down
Once squash has rested, use a dinner fork to scrape the squash out, lengthwise - careful! It will be hot!
Add squash to the frying pan and fold in with the onions, garlic and oil
Add tomatoes, 1/4 cup parmesan, basil, pepper and continue to stir, allowing enough time to ensure everything is nice and hot after adding the room temp tomatoes
Sprinkle with the remaining 1/4 cup parmesan
you may transfer the squash to a casserole dish, add mozzarella and broil until cheese is melted and bubbly if you desire