In a large pot or deep skillet, heat the olive oil over medium heat.
Add the chopped onion and sauté for 3-4 minutes until translucent.
Add the minced garlic and diced red bell pepper to the pot and cook for another 2 minutes, stirring frequently.
Pour in the vegetable broth and water, then add the dried penne pasta.
Stir in the dried Italian seasoning, salt, and black pepper.
Bring the mixture to a boil, then reduce heat to medium-low and simmer uncovered, stirring occasionally, for 10 minutes.
Add the thawed green peas to the pot and continue cooking for another 3-5 minutes, or until the pasta is tender and the liquid has mostly absorbed.
Remove the pot from heat and stir in the grated Parmesan cheese and chopped fresh parsley until well combined.
Adjust seasoning with additional salt and pepper if needed.
Serve hot, garnished with extra Parmesan and parsley if desired.