Just add mimosas and you've got brunch!
Preheat oven to 375° F.
Heat oil in a sauté pan and cook the onions for 5 minutes. Stir in the garlic and cook for another minute. Remove from heat to cool.
Roll out prepared pie crust and press into a 9-inch tart pan (with removable bottom), crimping the sides.
In a large bowl, whisk the eggs. Add in the cooked onion and garlic, and all remaining ingredients. Mix well. Pour into prepared tart pan and bake for 20 to 25 minutes, until center is set and crust is lightly browned. Serve warm or room temperature.