Creamy White Bean Gratin with Broccoli Rabe & Sausage

Ingredients

• 1/2 cup Bertolli^® Cooking Olive Oil divided
• 1 lb. fresh Italian sausage links
• 1 small yellow onion, finely chopped
• 1 small bunch broccoli rabe, tough stems trimmed
• Salt and pepper
• 1 3-inch sprig fresh rosemary,
• 1 cup chicken broth
• 1 cup Bertolli^® Garlic Alfredo with Aged Parmesan Cheese Sauce
• 2 (15.5-oz.) cans (cannellini) beans drained and rinsed
• 1 cup freshly grated Parmesan cheese, divided
• 2 cups coarse fresh breadcrumbs
• lemon zest finely grated