In a large skillet cook onion and yellow or red sweet pepper in hot oil until very tender. Set aside.
Place the bread shell on a lightly greased or parchment-lined baking sheet. Sprinkle ripe olives over bread shell. Top with onion mixture. Sprinkle with goat cheese, pine nuts or walnuts, and snipped oregano. Bake in a 400 degree F oven about 8 minutes or until heated through. If desired, top with whole oregano leaves. Makes 12 appetizer servings.