Heat the olive oil in a medium saucepan on medium heat

Saute the pancetta until crispy (skip this step if making it vegan)

Using a slotted spoon, take out the pancetta when finished cooking

Saute the onions in the saucepan in the leftover olive oil/pancetta fat until translucent. About 5-8 minutes

Next, saute the garlic and red pepper flakes in with the onions for about 1-2 minutes

Then pour the San Marzano tomato puree over the onion mixture in the saucepan

Salt and pepper the sauce to your liking

Let simmer for around 30 minutes

While the sauce is simmering, prepare your spaghetti squash, parsley, and Pecorino Romano cheese

Preheat your oven to 400 degrees Farenheit

Cut your spaghetti squash in half crosswise, not lengthwise (for longer spaghetti strands)

Drizzle each half with a tablespoon of olive oil each

Sprinkle with salt and pepper

Place spaghetti squash halves with cut-side down

Roast in the oven for 40-50 minutes until squash is tender and you can easily pierce a knife through it

Take spaghetti squash out and remove the seeds in the center of the halves (I like to scoop mine out with a grapefruit spoon that has sharper sides)

Using a fork, remove your spaghetti-like strands from each half

Spoon spaghetti squash onto a plate

Top with the Amatriciana sauce and sprinkle with some parsley and Pecorino Cheese

Serve and enjoy!