In a large skillet, heat a drizzle of olive oil over medium heat. Add diced green bell pepper and red onion with a teaspoon of salt, stirring occasionally. Sauté for about 10 minutes, or until the vegetables are softened and translucent.

Once your veggies are ready, stir in the pesto sauce along with ½ cup of reserved pasta water. Bring the mixture to a gentle simmer over medium-low heat for about 5 minutes.

In a small bowl, mix 2 tablespoons of all-purpose flour with a few tablespoons of warm water to form a slurry. Gradually pour this slurry into the skillet, stirring constantly to avoid lumps. Next, add 1 cup of heavy cream to the pan and let it simmer for 5-10 minutes.

Sprinkle in 1 teaspoon of garlic powder, 1 teaspoon of dried oregano, and fresh chopped parsley, stirring well to combine. Adjust seasoning with additional salt and black pepper as needed.

Once your penne pasta is cooked al dente, drain it before adding it directly to the skillet with the sauce. Toss everything together for about 5 minutes over low heat.

Carefully plate the creamy pesto sauce pasta, optionally topping with grated Parmesan cheese and extra parsley.