You will also need:
1/4 teaspoon salt, or to taste
1/8 teaspoon ground black pepper
1/4 teaspoon celery salt, or to taste
2 to 4 tablespoons vegetable broth or milk

Directions:

1. Peel the onions and cook them in boiling salted water until almost tender.
2. Remove onions from the water and take out the inner portions of the onions, leaving the outside layers in the shape of a cup.
3. Chop the portions of the onions which have been removed and set aside.
4. In a large frying pan, heat butter or olive oil on medium. Add chopped bacon, chopped onions, and garlic and sauté for 3 to 4 minutes.
5. Remove from heat; stir in crumbled Feta cheese, chopped olives and bread crumbs. Add 2 tablespoons vegetable broth or milk to the bread crumb mixture and stir in spices. Return mixture to the stove and cook for 2 more minutes. Taste and adjust seasonings if needed. If the stuffing is not moist enough, add in 1 to tablespoons of vegetable broth or milk to make the stuffing more moist.
6. Fill the onion shells with the stuffing, place in a baking dish and cover and refrigerate until needed or bake in hot oven until browned.
7. Serve immediately.

Makes 6 servings.