2 tsp black truffle oil (optional but makes a big difference., optional) (optional) or 2 tsp white truffle oil (optional but makes a big difference.) (optional)
Rub steaks with olive oil and sprinkle with kosher salt and allow to come to room temperature.
Place potatoes and scallions in a pot and add water to cover potatoes by at least one inch. Bring to a boil and strain once the potatoes are fork soft. Remove Scallions and discard. Return potatoes to pot and add butter and mascarpone cheese. Mash until smooth mixing in enough milk to thin to desired consistency. Mix in optional truffle sauce; season with salt and pepper. Transfer to bowl.
While potatoes are boiling, sauté the shallots in 1 1/2 tablespoons of butter until soft. Add the wine, cherries, blueberries, strawberry preserves, coffee, and chicken stock before the butter browns. Simmer for 15 to 20 minutes or until reduced to about 1/2 cup, stirring frequently. The sauce should be the consistency of heated jam. Set aside.
Grill steaks to your preference.
Carefully reheat the sauce and whisk in the final 1 1/2 tablespoon of butter.
Scoop potatoes in center of plate and place steak on top. Spoon sauce over steak. Enjoy!