Bring a large pot of salted water to a boil.

Add the penne pasta to the boiling water and cook according to package instructions until al dente, about 11 minutes.

Drain the pasta in a colander, reserving about a cup of pasta water.

In a large skillet, heat olive oil over medium heat. Add the chopped onion and sauté until translucent, about 5 minutes.

Stir in the minced garlic and cook for another minute until fragrant.

Add the diced tomatoes, oregano, and basil to the skillet. Stir and let it simmer for about 5-7 minutes.

Once the sauce has thickened slightly, add the drained penne to the skillet. Toss everything together, adding reserved pasta water as needed to reach desired sauce consistency.

Season with salt and pepper to taste, then remove from heat. Serve warm, topped with grated Parmesan cheese.