Slice eggplant lengthwise about 1/8 inches thick. Slice zucchini lengthwise a bit thinner. Salt, pepper and place in glass baking dish. Make sauce by combining balsamic vinegar, soy sauce, olive oil and sugar. Pour sauce over eggplant and zucchini. Add chopped oregano and sun dried tomatoes and mix with hands. Cover with foil. Bake at 350 for 20 minutes. Remove foil and bake an additional 5-10 minutes. Remove from oven and chop coarsely, add artichoke hearts. Serve on toasted sourdough slices.