Preheat oven to 350°F (180ºC). Mix soup with milk and pepper. Stir in green beans; pour into greased 1.5 L (1.5 qt) casserole dish. Bake for about 30 minutes or until heated through. Remove from oven and stir.
Meanwhile, prepare Buttery Homestyle Mashed Potatoes following package instructions; dollop over top of green bean casserole.
Preheat oven to broil; broil casserole for about 2 minutes or until heated through and golden brown. Scatter onions over top; sprinkle with chives.
Tip: Substitute thawed frozen green beans for canned beans if desired.
Recipe by Mashed Potatoes - Idahoan Foods LLC at https://idahoan.ca/?p=2335