Start by boiling a large pot of salted water. Once it's at a rolling boil, add in the penne pasta and cook according to package instructions until it’s al dente. Reserve half a cup of that starchy pasta water before draining.

While the pasta is cooking, season the chicken or shrimp with salt, pepper, and a teaspoon of Cajun seasoning. Heat one tablespoon of olive oil in a skillet over medium heat and sear the protein until fully cooked.

In the same skillet, add another tablespoon of olive oil and butter. Toss in the sliced bell peppers and minced garlic. Sauté for about 3–4 minutes until the peppers are softened.

Stir in the remaining Cajun seasoning, smoked paprika, and red pepper flakes into the sautéed veggies. Pour in the heavy cream and bring to a gentle simmer. Gradually stir in the grated Parmesan cheese until it melts smoothly.

Add the drained pasta and cooked protein into the skillet. Gently toss everything together until each piece of pasta is coated in the sauce. Add reserved pasta water as needed to reach desired consistency.

Taste and adjust seasoning as needed. Garnish with freshly chopped parsley or cilantro and squeeze lime juice over the top before serving.