Cook the pasta al dente according to the package instructions.
Combine the spices with 2 tablespoons of frying oil.
Cut the chicken into 1/2-inch (1.5cm) strips. Season with salt and pepper and rub with the spice mix.
Cut the bell peppers into 1/4 inch (7mm) strips and the onion into thin slices.
Heat 1 tablespoon of frying oil in a big frying pan over high heat. Add the chicken strips in an even layer. Don't stir for the first 1-2 minutes letting the chicken brown, then turn over and cook until the chicken is cooked through (don't cook the chicken for too long or it will be tough). Transfer the chicken to a plate.
Add another tablespoon of oil to the pan, then add the peppers and onion. Cook for a couple of minutes over high heat, until the peppers are lightly browned, then add the broth and lemon juice. Cook for a couple of minutes until the vegetables are tender but still a little bit crunchy. The broth should reduce its volume by about a half (it shouldn't evaporate completely - if that's the case - add more broth).
Add the chicken back to the pan, toss with the vegetables and cooked pasta. Season to taste with salt and pepper.