Dissolve yeast & sucanat in about 1/2 c water & set aside till yeast is foamy.
Combine rye flour, wholewheat flour, salt, oatbran, carob, carawy & fennel seeds.
In a separate bowl, combine the vinegar, molasses, oil & onion. Add wet ingredients to the dry ingredients & blend well. Add yeast & mix well. If the dough is too stiff or dry, add more water. If too sticky add more flour. Turn dough out onto a floured surface; flatten it out; shape it into a round, shallow loaf. Place loaf on a lightly oiled baking sheet, brush dough with oil & let it rise in a warm spot until the dough holds an imprint when gently touched (about 30 minutes). Bake at 375F for 35 to 40 minutes & cool on a wire rack. Lightly brush the top with oil.
Ron Pickarski, "Friendly Foods"