Bring a large saucepan of lightly salted water to a boil. Add pasta and cook for 8 to 10 minutes or until al dente; drain.
Combine milk and butter in a saucepan over medium heat. Simmer gently, stirring, until mixture has reduced to 1 1/2. Remove pan from heat; whisk in cheese, basil, oregano, chives and parsley. Cover and set aside.
Saute chicken in a large frypan until lightly browned on both sides. Stir in green and red capsicum and cook until vegetables are tender and chicken is no longer pink in the middle.
In a casserole dish combine the hot cooked pasta, chicken mixture and sauce. Mix well and serve immediately.