Cut pressed tofu into ¼ inch slices. Place in a single layer in a small pan and pour tamari over strips. Marinate in tamari for 15 to 60 minutes, turning occasionally to coat evenly. The longer the marination time, the stronger the flavor. Drain.
Heat vegetable oil in a skillet and fry tofu on both sides until lightly browned. Dip fried tofu slices in a bowl of sweet and sour sauce to coat both sides.
Lay strips in a single layer in a heavy baking pan or casserole dish. Bake at 400° F, on the lowest oven rack for 10 minutes. Turn strips with a spatula and bake an additional 10 to 15 minutes until the sauce is well baked in.
Serve hot with extra sweet and sour sauce on the side for dipping.