01 - Cook fettuccine in salted boiling water according to package directions. Drain and set aside, reserving 1/2 cup pasta water for adjusting sauce consistency.
02 - Combine chili powder, cumin, smoked paprika, garlic powder, salt, and black pepper in a small bowl. Rub spice mixture evenly over both sides of chicken breasts.
03 - Heat olive oil in a large skillet over medium-high heat. Add chicken and cook 5-7 minutes per side until cooked through and lightly charred. Remove from pan, let rest 5 minutes, then slice thinly.
04 - In the same skillet, add a drizzle of oil if needed. Sauté red onion, bell peppers, and jalapeño for 4-5 minutes until softened and slightly caramelized. Remove and set aside.
05 - Reduce heat to medium. Add butter to the skillet and melt. Add minced garlic and sauté 30 seconds until fragrant.
06 - Pour in heavy cream and milk. Bring to a gentle simmer, whisking occasionally. Stir in Parmesan cheese, salt, black pepper, and chipotle powder. Cook 3-4 minutes until smooth and slightly thickened.
07 - Add cooked pasta and reserved vegetables to the sauce, tossing to coat. Add a splash of reserved pasta water if sauce is too thick.
08 - Squeeze lime juice over the dish, top with sliced chicken, and garnish with chopped cilantro. Serve with extra lime wedges on the side.