- In a large pot, place quartered potatoes and cover with water.
- Bring to a boil and reduce heat to medium.
- Allow to cook about 20-25 minutes or until easily pierced with a fork.
- Remove potatoes from the pan and place in another container to keep warm.
- Bring the potato water back to a boil and add the shredded cabbage, allowing to cook for 5 minutes, or until limp.
- Strain cabbage thoroughly, place on clean dish towel and dry thoroughly.
- Dump the water and add potatoes back into the warm pan.
- Mash thoroughly, adding butter one tablespoon at a time and blending after each addition.
- In a microwave or saucepan, gently warm the cream.
- Whisk in the mustard.
- Slowly add to the potatoes, blending quickly.
- Add the cheese and stir until it melts.
- Add cabbage and scallions and season with salt and pepper, to taste.
- Add additional cream if needed.