Dip cubed tofu in soy sauce and sprinkle with pepper. Set on a lightly oiled baking dish for thirty minutes in the oven at 180C/355F. Turn halfway through to make sure all the sides get browned, then set aside.
In a deep skillet, brown the onions in oil. Lower heat and stir in carrots, tomatoes, potatoes, yams and seasoning. Add broth. Cover and simmer for 45 minutes, stirring occasionally. Add the peas and simmer until tender, then stir in tofu chunks.