Prep (5–10 minutes) Slice peppers and onion into thin strips. Cut chicken into bite-size pieces or thin strips. In a small bowl, mix your fajita seasoning (or open the packet). Shred your cheese now so you’re not doing it later with one hand while stirring with the other.

Brown The Chicken (3–6 minutes) Heat 1–2 tablespoons of oil in your skillet over medium-high. Add chicken in a single layer (work in batches if needed). Sprinkle with salt, pepper, and some fajita seasoning. Brown until the outside looks cooked and you get a little color. Move chicken to a plate. It will finish cooking later. Why remove it? Because chicken can go from juicy to dry in a blink when you keep it in a hot pan while you do other steps.

Cook The Peppers And Onions (5–8 minutes) Add a touch more oil if the pan looks dry. Add onions and peppers. Cook until they soften but still have a little bite. Add minced garlic in the last 30 seconds (garlic burns fast and turns bitter). Your kitchen should smell like fajitas right now. That’s the signal you’re on track.

Add Liquids + Pasta And Simmer (12–18 minutes) Pour in chicken broth and milk. Add tomatoes with green chiles (or your salsa choice). Stir, scraping up browned bits from the bottom (that’s flavor). Add dry pasta. Bring to a gentle boil, then reduce to a steady simmer. Now the key moves: Stir every 4–5 minutes so pasta doesn’t stick. Keep noodles mostly submerged. If sauce thickens too fast and pasta isn’t tender yet, add a splash of broth. Different pasta brands absorb liquid differently. That’s normal. You’re not doing anything wrong.

Finish Creamy + Serve (2–3 minutes) Return chicken to the skillet. Simmer 2–3 minutes until chicken is cooked through. Turn heat to low. Stir in cheese until melted and silky. Finish with lime right before serving. Top with cilantro, green onions, or avocado (optional).