In stand mixer fitted with a paddle attachment, add 1 cup bread flour, yeast, whole wheat flour, oats, salt, wheat germ, wheat bran and cornmeal; mix well. Add warm water, honey and oil to flour mixture. Blend on low speed for 30 seconds; beat on medium speed for 3 minutes.
Switch to dough hook attachment. Gradually stir in enough remaining flour to make a firm dough. Knead until smooth and elastic, about 5 to 7 minutes.(NOTE: For hand mixing: following above steps, mix ingredients in large mixing bowl using a wooden spoon or dough whisk. Knead on floured surface until smooth and elastic.) Place dough in lightly oiled bowl and turn to grease top. Cover; let rise until indentation remains after poking dough with finger down to second knuckle, about 1 hour.
Prepare baking dish: Grease a 1 1/2-quart casserole or soufflé dish; set aside
Turn dough onto lightly floured surface; punch down to remove air bubbles. Cut off 1/4 of dough. Cover, let dough relax for 10 minutes. Shape both pieces into smooth, round balls. Place larger ball in prepared dish. With fist, make deep indentation in center. Place smaller ball in well. Stick floured finger down through center of both balls to bottom of dish to help secure both balls together. Cover; let rise until indentation remains after lightly touching dough.
Preheat oven to 375°F.
Just before baking, stick finger into hole again. Bake for 35 to 40 minutes. Remove from dish; cool on rack.