Start by boiling a large pot of salted water. Once boiling, add the fettuccine pasta and cook according to package instructions until al dente. Drain and set aside.
In a large skillet, heat the olive oil over medium-high heat. Add the sliced chicken breast and season with salt, pepper, chili powder, cumin, and paprika. Cook until the chicken is browned and cooked through, about 5-7 minutes. Remove the chicken from the skillet and set aside.
In the same skillet, add the sliced onion and bell peppers. Sauté for about 5 minutes until they are tender and slightly caramelized. Add the minced garlic and cook for an additional 1-2 minutes until fragrant.
Return the cooked chicken to the skillet with the vegetables. Pour in the chicken broth and bring to a simmer. Then add the heavy cream, stirring to combine. Let it simmer for a few minutes until the sauce thickens slightly.
Add the cooked fettuccine to the skillet, tossing to coat it in the creamy sauce. Stir in the shredded cheddar cheese until melted and well incorporated. Taste and adjust seasoning with salt and pepper as needed.
Serve the Skillet Creamy Chicken Fajita Pasta hot, garnished with fresh cilantro for a burst of color and flavor.