1 (6-ounce) can albacore tuna in water, drained and flaked. 2 tablespoons low-fat mayonnaise (such as Hellman's) 2 tablespoons reduced-fat sour cream. 2 teaspoons tarragon vinegar. 3/4 teaspoon dried dill. 1/8 teaspoon salt. 1/8 teaspoon pepper. 4 (1-ounce) slices whole wheat bread, toasted.
Calvados is a French brandy made from distilling hard apple cider. For over a thousand years cider has been brewed in northwest France, specifically the Normandy region. Eventually the French took to distilling their cider as many other societies did with their fermented beverages.
Calvados is often called for in British and other European recipes, where it is a little more commonly used than it is in the US. In a recipe, it can be be used much like a flavored extract, and only a small amount of it needs to be added to a recipe to give it some extra flavor.