Heat 1 tablespoon of olive oil in your large skillet over medium-high heat. Add the thinly sliced chicken breast to the pan, seasoning it with half of the chili powder, cumin, paprika, salt, and pepper. Cook the chicken until it’s no longer pink and starts to turn golden, about 5-6 minutes. Remove the chicken from the pan and set it aside.
In the same pan, add the sliced bell pepper and onion. Stir occasionally, cooking until they soften and develop a bit of char, roughly 5 minutes. Add the minced garlic and the remaining spices, cooking for another minute until fragrant.
Pour in the undrained diced tomatoes and the chicken broth. Stir well, scraping up any browned bits from the bottom of the pan. Nestle the fettuccine pasta into the liquid, making sure it’s mostly submerged.
Bring the mixture to a gentle boil, then reduce to medium-low heat. Cover with a lid and let it simmer, stirring every few minutes to prevent sticking. Cook for about 12-15 minutes or until the pasta is tender and most of the liquid has been absorbed.
Once the pasta is cooked, stir in the corn and the cooked chicken slices. Sprinkle the shredded cheese over the top and cover again for a couple of minutes, allowing the cheese to melt into the creamy mixture.
Remove from heat. Top the pasta with diced avocado and fresh cilantro if desired. Serve warm and enjoy the satisfying blend of fajita flavors and creamy pasta comfort.