Pre-heat the oven to 180°C (350°F).
Place the pie on a baking sheet and bake for 1 hour.
Meanwhile, make the mashed potatoes and peas according to your favourite method.
Remove the pie from the oven and serve directly to the table with the homemade horseradish ketchup, marinated beets and mashed potatoes and peas.
Place the ketchup and horseradish in a small bowl. Add a few drops of Tabasco sauce to taste. Mix well.