01 - Pound the chicken breasts to even thickness. Rub both sides generously with Cajun seasoning, pressing the spices into the meat to ensure adherence.
02 - Heat olive oil in a large skillet over medium-high heat until shimmering. Add seasoned chicken and cook for 5–6 minutes per side until golden-brown crust forms and internal temperature reaches 165°F. Transfer to a plate, cover loosely with foil, and allow to rest for 5 minutes.
03 - Bring a large pot of salted water to boil. Cook fettuccine according to package directions until al dente. Reserve ½ cup of starchy pasta water before draining thoroughly.
04 - In the same skillet used for chicken, melt butter over medium heat. Add bell peppers and onion, sautéing for 3–4 minutes until softened and slightly caramelized. Stir in minced garlic and cook for 1 minute until fragrant, being careful not to burn.
05 - Pour in heavy cream and chicken broth, using a wooden spoon to scrape up browned bits from the bottom of the skillet. Bring mixture to a gentle simmer, stirring occasionally.
06 - Add Parmesan cheese and smoked paprika to the simmering liquid. Stir continuously until cheese completely melts and sauce thickens enough to coat the back of a spoon. Season with salt and pepper to taste.
07 - Slice the rested chicken breasts across the grain into ½-inch strips.
08 - Add drained pasta directly to the skillet with the sauce. Toss vigorously to coat each strand thoroughly, adding reserved pasta water a tablespoon at a time if sauce becomes too thick. Top with sliced chicken strips. Garnish generously with chopped fresh parsley and additional Parmesan cheese. Serve immediately while hot.