In a large bowl, whisk together 4 cups flour, sugar, baking soda and sea salt. Using your fingertips, work 4 tablespoons cubed butter into the dry ingredients until the mixture resembles coarse crumbs. In a medium bowl, whisk together buttermilk, egg and orange zest. Pour wet ingredients into dry ingredients, and stir just until combined. Don’t over mix here. Stir in the currants with whiskey and fennel seeds.