Pre-heat oven to 350 degrees. Butter 2-3 quart casserole dish. Leave broccoli frozen and break up when mixing it in with tuna and other ingredients.
Mix tuna & all but last 4 ingredients together lightly. Add to buttered dish. Mix breadcrumbs, parsley together sprinkle onto of tuna mixture then drizzle butter over breadcrumb mix. Sprinkle cheese all over casserole then bake for 45 min.