For the mashed potatoes: Boil potatoes until fork tender. Drain and whip with remaining ingredients.
For the sauce: Place all ingredients is a saucepan. Bring to a simmer and cook until carrots are tender. Puree in a food processor, and push through a chinois.
For the glaze: Heat soy sauce and sugar in a saucepan until sugar is dissolved.
Assembly: Sear tuna in a hot pan or grill. Place on a plate and glaze. Surround with carrot ginger sauce and serve with mashed potatoes.
Recipe courtesy of Temple Bar and Grill, Atlantic City, NJ