Preheat oven to 400°F (200°C).
Cut the spaghetti squash in half lengthwise and scoop out the seeds.
Drizzle the cut sides with 1 tablespoon of olive oil and season with salt and pepper. Place cut side down on a baking sheet.
Roast in the preheated oven for 40-45 minutes, until the flesh is tender and easily scraped into strands with a fork.
While the squash is roasting, heat 1 tablespoon of olive oil in a skillet over medium heat.
Add the garlic and cook until fragrant, about 1 minute.
Add the bell pepper, zucchini, and yellow squash to the skillet. Cook until tender, about 5-7 minutes.
Add the cherry tomatoes, oregano, and basil. Cook for another 2-3 minutes until the tomatoes are softened.
When the squash is done, use a fork to scrape the flesh into spaghetti-like strands.
Toss the squash strands with the cooked vegetables. Season with salt and pepper to taste.
Serve with grated Parmesan cheese, if desired.