01 - Preheat oven to 400°F. Cut bagels into bite-sized pieces and spread them evenly in the bottom of a greased 9×13 inch baking dish, arranging in a single layer for even baking.
02 - Place cream cheese and cream in a medium saucepan on medium-low heat and whisk until no lumps remain, whisking constantly to prevent sticking.
03 - Add the cooked, shredded chicken to the cream cheese mixture and stir until all the chicken is coated. Remove from heat.
04 - In a small mixing bowl, combine diced tomatoes, diced red onion, basil pesto, salt, pepper, and parmesan cheese. Mix gently to combine without crushing the tomatoes.
05 - Spread the chicken and cream cheese mixture evenly over the bagel pieces in the baking dish. Then, top with the bruschetta mixture, distributing evenly for balanced flavors.
06 - Sprinkle the grated mozzarella cheese evenly over the casserole for a gooey topping.
07 - Place the casserole in the preheated oven and bake for 30 minutes, or until the cheese is melted and bubbly and the casserole is heated through.
08 - Allow the casserole to cool for a few minutes before cutting and serving to let it set slightly.