The original of this recipe made enough onion and olive tart to feed an army. This recipe is just right for a small gathering of family and very good friends. smaller slices are wonderful for appetizers, and large slices make a good main course for lunch with a salad of crisp greens. Note: You may want to chose a square or rectangular tart pan for a different presentation.unknown source
To make crust, coat an 8 inch round tart pan with vegetable spray roll out pastry dough. fit dough into bottom of tart pan and trim, leaving a 3/4 inch overhang. Chill in refrigerator while you make the filling.
Heat butter and oil in skillet over medium heat. Add onion and cook, stirring with wooden spoon, til translucent, 5 to 7 minutes. Remove pan from heat. Add garlic salt, pepper, 1/2 tsp. of thyme leaves, flour, olives, and Parmesan cheese and stir to mix.
In another bowl, beat 2 of the eggs. Add a small amount of onion mixture and stir quickly to temper eggs. Add remaining onion mixture and stir to mix. Allow filling to cool.
Set oven rack in middle position. Preheat oven to 350.
Add cooled filling to tart pan. Beat remaining egg and brush onto edges of pastry shell. Put tart on foil lined baking sheet and bake 35 to 40 minutes or til top is set. sprinkle with remaining 1/2 tsp. frsh thyme leaves. Cut into wedges and serve at once. Store leftovers covered with wax paper in refrigerator. Reheat in low oven. Makes 4 main course servings, or 6 to 8 first course servings.