Peel and cube potatoes. Microwave in Multipurpose Steamer, covered, on high for 8–10 min.
Meanwhile, brown beef in a fry pan over medium-high heat. Stir in seasoning mixture. Bring to a boil, reduce heat, and stir while simmering for 2 min. Stir in vegetables and heat through.
Using the Ground Meat Separator, mash potatoes with milk. Top meat mixture with potatoes and chives or green onions, if desired.