Preheat the oven to 350 °. Grease a 10-inch round baking dish.
In a medium mixing bowl, combine the celery soup, sour cream, and 1/3 cup asiago cheese. Stir in the green beans.
Spoon the mixture into the prepared pan. Sprinkle with the remaining 1/3 cup asiago cheese.
In a small dish combine the panko and the melted butter. Sprinkle this mixture evenly over the cheese.
Bake for 45 minutes or until bubbly and the top is light golden.
Top with the green onions and parsley and serve immediately.
To freeze: The casserole can be wrapped and frozen prior to baking. Be sure to chill the soup and do not thaw the green beans before assembling. Thaw the casserole in the refrigerator before baking.Drained, canned green beans can be substituted for frozen.