Cook the Pasta: Bring a large pot of generously salted water to a rolling boil. Add the penne and cook according to the package directions until al dente (firm to the bite). Before draining, reserve about ½ cup of the starchy pasta water. Drain the pasta and set it aside.
Prepare the Chicken: In a medium bowl, toss the chicken cubes with 1.5 tablespoons of jerk seasoning until they are evenly coated. Heat 1 tablespoon of oil in a large, heavy-bottomed skillet or pan over medium-high heat. Add the chicken in a single layer, being careful not to overcrowd the pan. Cook for 5–7 minutes, stirring occasionally, until the chicken is golden brown and cooked through. Remove the chicken from the pan and set it aside on a plate.
Sauté the Vegetables: In the same skillet, add the remaining tablespoon of oil. Add the sliced bell peppers and cook for 3-4 minutes, stirring frequently, until they are slightly softened but still have a bit of a crunch. Add the sliced green onions and minced garlic, and cook for another 30 seconds until fragrant.
Build the Creamy Sauce: Sprinkle the remaining 1.5 tablespoons of jerk seasoning over the vegetables and stir to combine. Pour in the stock, using a wooden spoon to scrape up any flavorful browned bits from the bottom of the pan. Lower the heat to medium-low, then stir in the heavy cream.
Combine and Simmer: Return the cooked chicken to the skillet. Let the sauce gently simmer for 3–5 minutes to allow the flavors to meld together. Gradually stir in the grated Parmesan cheese until it is fully melted and the sauce is smooth.
Toss and Serve: Add the cooked pasta to the skillet and toss everything together until the pasta is thoroughly coated in the creamy jerk sauce.[8] If the sauce seems too thick, add a splash of the reserved pasta water to reach your desired consistency. Taste and adjust the seasoning if necessary. Garnish and Enjoy: Remove the pan from the heat. Garnish with fresh green onions or chopped parsley and serve immediately.