1 3/4 cups unbleached all-purpose flour
1 cup whole wheat flour, plus more for shaping
3 T cold unsalted butter, cut into small pieces
2 teaspoons baking soda
1 3/4 teaspoons salt
1/4 cup wheat bran AND 1/4 cup oat bran OR 1/2 cup 7 Grain Hot Cereal OR 1/2 cup oats
1/4 cup untoasted wheat germ
2 T flax seeds
1/3 cup raw sunflower seeds
1 large egg
About 1 3/4 cups buttermilk
2 T honey
Adjust an oven rack to the center position and preheat the oven to 425°F. Lightly oil a heavy baking sheet or cast iron pan or line it with a silicone baking sheet.
In a large bowl, stir together the all-purpose flour and whole wheat flour. Add the butter and work it into the dry ingredients with your fingertips until the fat particles are very fine. Stir in the baking soda, salt, wheat bran & oat bran (or substitutes), wheat germ, flax seeds, and sunflower seeds.
Beat the egg lightly with a fork in a 2-cup glass measure. Add enough buttermilk to come to the 2-cup line. Add the honey and combine well.
Add the liquid to the dry ingredients and stir with a wooden spoon or rubber spatula until the dough gathers into a thick, wet-looking mass.
Sprinkle your work surface with whole wheat flour and scrape the dough onto it. Dust the dough with a bit more whole wheat flour. Pat the dough into a circular shape about 7 inches across and 2 inches high and transfer it to the prepared baking sheet. Don't be concerned about evenness—the loaf should look rustic. Make a cross-shaped indentation on top of the loaf going right to the edges. I use a metal bench scraper.
Bake the bread for about 40 minutes, until it is well browned and sounds hollow when rapped on the bottom.
Cool for about 10 minutes before serving.