Bring a large pot of lightly salted water to a boil. Add pasta and cook until al dente, 8 to 10 minutes. Drain.
Cut chicken breast into strips. Place chicken and Cajun seasoning in a plastic bag. Shake to coat.
Melt butter in a large skillet over medium heat. Add chicken and cook, stirring, until browned and almost cooked through, 5 to 7 minutes.
Add bell peppers, mushrooms, and green onion. Cook, stirring, 2 to 3 minutes.
Reduce the heat and stir in cream, basil, lemon pepper, salt, garlic powder, and black pepper. Heat through. Add cooked linguine, toss, and heat through.
Sprinkle with Parmesan and serve.
