Add olive oil to a large saute pan along with red pepper (if using), and saute for about 1 minute over medium heat until fragrant.
Add diced onion and sliced garlic and continue cooking for about 3 or 4 more minutes OR until onion becomes translucent and darkens slightly.
Add frozen peas to the pan and saute until they have defrosted. Then add enough water to cover the peas, cover the pan with the lid ajar, and cook for about 20 minutes or until the level of desired tenderness is reached. I like my peas nice and creamy so cook until you reach this texture if desired.
Continue adding water to keep the mixture from drying out, help tenderize peas, and impart the onion flavor.
After the peas have been cooked, add the dried pasta to the pan and the salt, and then pour enough extra water to fully submerge the pasta and peas with about 1-inch of extra water on top.
Give everything a good stir, cover, boil, and cook pasta according to package instructions. You may uncover or place the lid ajar after the mixture boils. Adjust the heat if necessary.
Add black pepper to taste and about half the cheese. Stir well. Adjust for salt.
After cooking, ladle pasta with peas into bowls and add some warm chicken broth if desired.
Garnish with plenty more grated cheese and plenty of black pepper.
Serve immediately (if serving later, pour off and reserve broth so that the pasta will not continue absorbing the broth).