Combine the butter with the garlic and brush on the inside of the ciabatta rolls. Toast the rolls on a grill, or broil in the oven until crispy. Smear with Horseradish Mayonnaise.
Dip the tri-tip slices into the hot Jus for 45 seconds to warm. Pile the meat onto the bottoms of the rolls and top with cheese if using. Close the sandwiches, slice in half and serve with extra Jus on the side for dipping.
Combine the sour cream, horseradish, mayonnaise, garlic, lemon juice and 1/2 teaspoon salt in a medium bowl. Refrigerate until ready to use.
Heat a medium saucepan over medium heat. Saute the shallots and garlic in the butter and olive oil until lightly caramelized, 6 to 8 minutes. Add the flour and mix together to form a loose paste (roux). Deglaze with the brandy and whisk in the beef stock, demi-glace and Worcestershire sauce. Bring to a boil, then reduce the heat and simmer until the aroma and flavor of the jus are rich and deep, 25 minutes. Strain the broth to remove the garlic and shallots, then return the liquid to the pot. Season with salt and pepper and keep warm.
Season and grill the tri-tip to medium rare, then chill it so it is easier to slice thin. Make the jus ahead of time; when you reheat it, you can fortify it with any off-cuts from the tri-tip. Garlic butter and horseradish mayonnaise can be made a day or two advance. Simply store them in an airtight container in the refrigerator or cooler.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.
Recipe courtesy of Lackland Air Force Base, San Antonio, TX