Cook pasta according to directions. Once done and drained, add pasta to bottom of casserole dish.

Add tuna, onions, cream of chicken, chicken broth, peas, mozzarella cheese and pepper and mix well.

In a small bowl add bread crumbs and melted butter. Stir until all breadcrumbs are moist and crumble over top of mixture.

Cook at 375° for 25 minutes or until topping is golden brown. Remove from oven and allow to cool for a few minutes before serving as casserole will be hot.