Cook pasta in a large saucepan of boiling, salted water following packet instructions.
Meanwhile, heat 1 tablespoon oil in a large, non-stick frying pan over a medium-high heat. Add mushrooms, cook, stirring occasionally 5 minutes or until just start to colour. Remove to a plate. Add 2 teaspoons oil and half the chicken. Cook, stirring occasionally, for about 3 minutes, or until browned. Remove to a plate. Repeat with oil and remaining chicken.
Add remaining oil to the hot pan with onion. Cook, stirring occasionally for 4 minutes until soft. Add seasoning. Cook, stirring for 30 seconds. Add the capsicum, pasta sauce and stock. Return mushrooms and chicken. Bring to simmer, simmer gently for 2 minutes, or until chicken is cooked through.
Drain the pasta reserving 1 cup cooking liquid. Return the pasta to the pan, add the mushroom mixture, stir to combine, adding the reserved cooking liquid to adjust the consistency to your liking. Stir through parsley, season. Spoon into bowls, top with sour cream and crumble over corn chips. Serve.