8 medium potatoes, peeled and cut into quarters
1/2 cup cream cheese
1/2 cup sour cream
1/4 cup butter
1/4 cup milk
1 teaspoon salt
1/2 teaspoon freshly ground black pepper (optional)
1 1/2 cups shredded cheddar cheese, divided
8 slices beef, cooked, chopped, divided
1/2 bunch green onions, sliced
Place potatoes in saucepan, and cover with salted water. Bring to a boil over med-high heat. Cook until tender, then drain well.
Preheat oven to 375° degrees F.
Transfer potatoes back to the saucepan. Masher with a potato masher until almost smooth. Add cream cheese, sour cream, butter, milk, salt and pepper. Continue mashing until smooth. Stir in 1 cup of the cheese and half the beef. Spoon mixture evenly into a lightly oiled 3-quart casserole dish. Use a spatula or fork to make an irregular surface
Bake for 20 minutes. Top with remaining cheese, beef and green onions. Bake for 5 more minutes to melt cheese. Serve immediately.