Cook pasta according to package directions. Drain well.
Meanwhile, in a small bowl combine basil, garlic powder, rosemary, salt and pepper and set aside. Place 3 tablespoons flour in a shallow dish and add 1 heaping tablespoon of the seasoning mixture. Reserve the remaining seasoning mixture for later.
Coat the bottom of a large skillet with olive oil and place over medium high heat. Lightly coat chicken in seasoned flour, shaking off excess, and add to pan. Cook for about 2 to 3 minutes per side, or until golden brown and cooked through. Cook in batches if necessary. Remove chicken from skillet and keep warm. Discard any remaining seasoned flour mixture.
Add a little more olive oil to the skillet, add onion and cook and stir for about 3 minutes until softened. Add 1/2 teaspoon minced garlic. Cook and stir for another minute. Add the diced tomatoes, chicken broth, and reserved seasoning mixture to the skillet. Stir 2 tablespoons of flour into the half and half and mix until smooth. Add this mixture to the skillet. Bring to a simmer, stirring occasionally. Reduce heat to low and return chicken to the skillet and cook till heated through.
Serve chicken and pan sauce over pasta. Garnish individual servings with Parmesan cheese, if desired.
Adapted from McCormick Gourmet