Baked Penne with Chicken and Sun-Dried Tomatoes

INGREDIENTS

• 6 tablespoons butter, plus more for baking dishes
• Coarse salt and ground pepper
• 1 pound penne rigate
• 1 teaspoon olive oil
• 2 boneless, skinless chicken breast halves (8 ounces each), halved horizontally
• 1/2 cup plus 2 tablespoons all-purpose flour (spooned and leveled)
• 4 garlic cloves, minced
• 6 cups whole milk
• 10 ounces white mushrooms, trimmed and thinly sliced
• 1/2 cup oil-packed sun-dried tomatoes, drained and thinly sliced
• 1 1/2 cups shredded provolone (6 ounces)
• 1 cup finely grated Parmesan (4 ounces)