Twice Baked Potatoes piled high with shredded beef, caramelized onions, peppers, and mushrooms, and topped with Homemade Cheese Whiz! 'One whiz with' coming up!
Preheat oven to 400°F. Pierce potatoes all over with a fork. Rub vegetable oil over the potatoes, and place them on rimmed baking sheet. Sprinkle with salt and pepper. Bake potatoes for about 1 - 1 ¼ hours, or until a fork is easily inserted.
Combine all ingredients in a medium bowl. Set bowl over pot of simmering water to create a double boiler. Whisk gently until cheese melts and mixture is smooth. Remove from heat. Makes about 1 ¼ cups. (Can be made 1 day ahead. Cover and refrigerate. Rewarm over low heat, or microwave, when ready to use.)
In the same skillet, heat 1 tablespoon oil over medium-high heat. Add mushrooms and rosemary, and sauté 5 minutes, or until mushrooms are tender, stirring frequently. Add garlic and cook 1-2 minutes, stirring frequently. Season to taste with salt and pepper. Transfer to separate bowl and cover with foil. (Can be made 1 day ahead. Cover and refrigerate.)
When potatoes are cool enough to handle, cut off the top third and scoop the soft potato into a large bowl, leaving a ¼-inch rim throughout the potato shell.
Mash the potato with half of the steak, ½ cup whiz, and ½ cup milk. Season to taste with salt and pepper. Slightly mound the potato shells with mashed filling. Arrange potato tops on a rimmed baking sheet. Spread a little whiz over each. Set stuffed potatoes on the potato tops. (Can be made 1 day ahead of final baking. Tent with foil and chill. Let sit at room temp for 1 hour before continuing.) Top the potatoes with remaining steak, more whiz, and sautéed onion, peppers, and mushrooms, as desired. Bake in 400°F oven until heated through, 10-15 minutes. Transfer potatoes to platter and serve. Pass remaining Whiz separately.