Created by CanuckCooker on October 28, 2012
Step 1: Preheat oven to 375° F and lightly butter an 8-cup (2 litre) casserole dish.
Step 2: In a medium saucepan, over medium heat, melt butter. With a wooden spoon stir in flour, cook stirring until the mixture smells slightly nutty (but does not colour), about 2 minutes. While constantly whisking, slowly add 1/2 cup milk, until absorbed. Gradually, whisk in 1/2 cup of milk and continue to whisk constantly until absorbed. Whisk in milk in 2 more additions and bring to a simmer, whisking often.
Step 3: Reduce heat to low and gradually stir in Asiago cheese and 1 cup mozzarella cheese; stir until melted. Stir in green beans, chicken, olives, sundried tomatoes and basil. Warm through and stir in pasta. Season to taste with salt and pepper.
Step 4: Spoon pasta into prepared casserole dish and sprinkle with breadcrumbs mixed with remaining 1/4 cup mozzarella cheese.
Step 5: Bake uncovered for 15 to 20 minutes, or until edges of casserole are bubbling. Spoon into dishes to serve.