Begin by dicing about one pound of chicken or shrimp into bite-sized pieces. Chop one cup of bell peppers into strips and finely mince two cloves of garlic along with half a medium onion. Measure out your Cajun seasoning, red pepper flakes, and heavy cream in advance to streamline the cooking process.

In a large pot, bring four quarts of salted water to a rolling boil over high heat. Add 12 ounces of penne pasta and cook until al dente, typically around 8-10 minutes, stirring occasionally. Once done, drain the pasta in a colander and set aside, lightly toss with a bit of olive oil to prevent sticking.

In a large skillet, heat two tablespoons of olive oil over medium heat. Add the minced garlic and chopped onion, stirring frequently for about 2-3 minutes until fragrant and translucent.

Introduce the diced chicken or shrimp into the skillet, cooking for about 4-5 minutes until golden brown and cooked through.

Once the protein is cooked, add the chopped bell peppers to the skillet. Continue cooking for 3-4 minutes, stirring occasionally, until they soften slightly.

Pour in one cup of heavy cream along with your prepared Cajun seasoning and red pepper flakes. Stir together and let the sauce simmer for about 5 minutes on low heat, allowing it to thicken.

Add the drained penne pasta directly into the skillet with the sauce, tossing gently to combine thoroughly. If too thick, add reserved pasta water gradually until the desired consistency is achieved.

Remove the skillet from heat. Serve hot, garnishing with your choice of cheese and a sprinkle of black pepper or additional Cajun seasoning.