Into a large mixing bowl, add the all-purpose flour, granulated sugar, sea salt, baking powder, and baking soda. Whisk to combine.
Add butter then use your hands to rub it into the dry ingredients until the mixture is crumbly.
Stir in dark chocolate and candied orange peel.
Add prepared flax mixture and buttermilk. Stir just until incorporated.
Transfer dough to the prepared baking sheet and arrange in a round shape approximately 7-8 inches in diameter.
Bake 1 hour 10 minutes, until a toothpick inserted in the center comes out clean.
Remove from the baking sheet and place on a cooling rack.
Allow the bread to cool completely before slicing.