Cut the chicken into 1 cm cubes. Season the chicken with 2 tbsp of fajita seasoning and let it marinate for at least 30 minutes, or overnight for deeper flavor.
Boil a large pot of water over high heat. Once boiling, add 0.5 tsp of salt and the pasta. Cook the pasta according to the package instructions.
While the pasta is cooking, chop the onions finely and cut the bell pepper into small cubes. Heat a pan to slightly above medium heat and add a drizzle of olive oil. Add the chopped onion and sauté for 3-5 minutes until it becomes slightly brown and fragrant.
Add the chopped bell pepper to the pan and cook for about 5 minutes, stirring occasionally, until the pepper softens.
Add the marinated chicken to the pan and cook for about 5-7 minutes, stirring occasionally, until the chicken is lightly browned and cooked through.
Add the chopped garlic to the pan with the chicken and vegetables, and cook for about 1 minute until fragrant.
Add the cream cheese to the pan, followed by pasta water. Mix well to create a smooth sauce. Then, pour in the light cream and stir again until well combined. Cook the sauce for about 3-4 minutes.
When the first bubbles appear in the sauce, add the remaining 0.5 tbsp of fajita seasoning and grated cheese. Mix well to melt the cheese into the sauce. Then, add the Maggi spices and cook for about 3 more minutes, or until the sauce thickens to your desired consistency.
Add the cooked pasta to the pan and mix well to coat the pasta evenly with the sauce.
Serve the pasta on a plate, sprinkling additional cheese on top and adding chili (optional).