Preheat oven to 400 degrees.
In pot of boiling water, cook potatoes for about 15 minutes or until tender.
Drain well and return to pot. Add margarine and half of the fresh ground pepper and mash until smooth; set aside.
In a nonstick skillet, heat oil over medium heat. Cook ground round, green pepper and garlic, stirring for 5 minutes. Stir in flour and cook, stirring, for 1 minute.
Add stock to skillet; bring to a boil. Add peas, corn, carrots, and remaining ground pepper.
Spread mixture into 8-inch square baking dish. Spread mashed potato over top. Bake for about 15 minutes or until bubbly around the edges.