In a large bowl, combine the flours, salt, and yeast; make a well in the center and add the buttermilk, egg, and melted butter and stir to combine roughly. Add the oatmeal and knead or stir for several minutes until the batter is smooth and elastic but still sticky. Place in a large greased bowl and let rise until dough doubles in size, about an hour.
Grease two bread pans. Divide the dough between the pans, smooth the tops with wet hands, cover with greased plastic wrap and let rise until the bread is about 1/2 inch above the rim of the pans, about 1 hour.
Bake in a pre-heated 375 degree oven for 45 minutes, until the loaves are golden brown on top and make a hollow sound when thumped on the bottom. Remove from pans and cool on a wire rack for at least 30 minutes before slicing.