In a large pot, heat 2 tablespoons of olive oil over medium heat.
Add thinly sliced onions and sauté until translucent.
Stir in minced garlic and red pepper flakes, cooking for an additional minute.
Add 12 oz of your chosen pasta, 1 can of diced tomatoes (with juices), 1 teaspoon of dried oregano, 1 teaspoon of dried basil, and a pinch of salt and pepper to the pot.
Pour in 2 cups of vegetable or chicken broth and give everything a good stir.
Increase the heat slightly and bring the mixture to a gentle boil.
Reduce the heat to a simmer, cover the pot with a lid, and let it cook for about 10-12 minutes, stirring occasionally. Cook until the pasta reaches your preferred level of doneness.
After the pasta has simmered, add the diced mushrooms to the pot and stir them in.
Taste the pasta and adjust the seasoning with additional salt and pepper if desired.
Serve the One Pot Pasta hot, garnished with fresh basil leaves and grated Parmesan cheese.