For the sauce:
— 1/4 cup honey
— 2 tablespoons brown sugar
— 1/2 cup red wine vinegar
— 1/2 cup soy sauce
— 1 tablespoons sesame oil
— 2 tablespoons freshly ground black pepper
For the steak:
— 1 ½ pounds flank steak trimmed (see note 1)
— Salt to taste
— 3 tablespoons vegetable oil divided
— 2 bell peppers any color, stemmed, seeded, and thinly sliced
— 1 onion halved and thinly sliced
— 3 cloves garlic minced
— 1 tablespoon fresh ginger minced
— 2 teaspoon cornstarch
For The Mashed potatoes :
— 4 pounds Russet Potatoes about 8 medium
— 1/2 cup butter melted (1 stick)
— 1/2 cup sour cream
— 6 ounces cream cheese softened
— 2 garlic cloves minced
— 8 ounces white cheddar cheese grated, divided (about 2 ½ cups)
— 3 ounces Parmesan cheese grated or shredded (about ½ cup)
— Kosher salt
— 1/4 teaspoon pepper
— fresh minced parsley or chives for garnish if desired
To make the sauce:
In a medium bowl, whisk together honey, brown sugar, red wine vinegar, soy sauce, sesame oil, and black pepper to taste (I like 2 tablespoons; use less if you don’t love black pepper).
Measure out ¼ cup of this sauce and pour it into a large zipper-top plastic bag or glass bowl for marinating the meat. Reserve the remaining sauce for the stir-fry.
To make the steak:
Freeze steak for 15 to 20 minutes, just until the outside is chilled, but the steak is not frozen solid. This will make it easier to slice the steak thinly.
Remove the steak from the freezer and slice thinly against the grain. Add the steak to the large plastic bag or bowl with the marinade and marinate at room temperature at least 10 minutes or up to 1 hour.
Remove the steak from the plastic bag, discarding the marinade, and pat dry with paper towels. In a large skillet over medium-high heat, heat 1 tablespoon vegetable oil until shimmering. Season half the meat with ¼ tsp salt, add to the skillet in a single layer, and cook for 1 minute without stirring, until browned on one side.
Stir the meat and continue to cook for 1 minute longer, until browned all over. Transfer to a clean bowl. Wipe out the skillet, add another tablespoon of vegetable oil, and repeat with the remaining steak.
When the meat has been cooked and set aside, wipe out the skillet. Add the last tablespoon of vegetable oil and heat until shimmering. Add the peppers and onions and stir-fry until tender-crisp and still bright, about 3 to 5 minutes.
Meanwhile, stir the cornstarch into the reserved stir-fry sauce. Clear a space in the middle of the vegetables. Add the garlic and ginger to the skillet and mash together, then mix in to the vegetables.
Return the steak and any accumulated juices to the skillet. Pour in the reserved stir-fry sauce and cook over medium-high heat until the sauce boils and thickens slightly, about 2 minutes. Remove from heat and serve over mashed potatoes.
To make the Mashed potatoes:
In a 5 quart pot, boil about 2 inches of water. Once boiling, add 1 tablespoon of salt. (Water should be enough to cover the potatoes, so add as much as you think you need – you can always scoop some out if it’s too much)
Rinse, peel, and dice potatoes into chunks.
Place potatoes into boiling water and cover (but keep the cover just slightly open to let steam escape). Cook over medium-low heat for 20-25 minutes, or until potatoes are fork tender. They should almost fall apart when pierced with a fork.
Remove from heat and drain.
Place potatoes back into the pan and sprinkle with 1 teaspoon salt. Add softened butter and mash well.
In a large mixing bowl by hand or with a hand mixer, beat cream cheese, white cheddar cheese (reserve about ¾ of a cup for topping Parmesan cheese together on low speed until smooth. Stir in sour cream, minced garlic and black pepper.
Stir cheese mixture into mashed potatoes just until combined; don’t over mix or the potatoes will become gummy. Spread potatoes into a 2 or 3 quart greased casserole dishes and top evenly with remaining white cheddar cheese.
Cover with nonstick foil and refrigerate for up to 24 hours. When ready to heat, bake at 350 degree F, covered, for 20 minutes, then remove foil and bake an additional 20-25 minutes or until cheese is melted and potatoes are warmed through. *If baking immediately, while potatoes are still hot, reduce cooking time by 15 minutes and leave uncovered.
Garnish with fresh minced parsley or chives if desired before serving.