Heat the Dutch oven over medium heat and add the olive oil.
Add the sliced onion and garlic to the Dutch oven and sauté for 3 to 4 minutes until softened and fragrant.
Pour in the crushed tomatoes and vegetable broth.
Add the dried spaghetti, dried oregano, dried basil, red pepper flakes, salt, and black pepper to the pot.
Use a wooden spoon to press the pasta down into the liquid as much as possible to submerge it.
Bring the mixture to a boil over medium-high heat.
Once boiling, reduce the heat to medium-low and simmer uncovered, stirring occasionally, until the pasta is cooked and most of the liquid has been absorbed, about 12 to 15 minutes.
Remove the Dutch oven from heat and stir in the grated Parmesan cheese and chopped fresh basil.
Let the pasta sit for 2 minutes to thicken slightly before serving.