Place chicken and Cajun seasonings in a bowl and toss to coat. In a large skillet, over medium heat, saute chicken in butter until chicken is tender, about 5-7 minutes. Reduce heat and add green onion, heavy cream, tomatoes, basil, salt, garlic powder, and black pepper and heat through. Pour over hot linguine and toss with Parmesan cheese, If sauce is too thick, add a little more cream to desired consistency.