Preheat oven to 350 degrees.
Butter a 9 inch deep dish pie plate and set aside.
In a large skillet, cook bacon until crisp. Remove from pan and drain on paper towels. Crumble when cool.
In the same skillet, sauté the chopped onion for about 4 minutes until translucent. Add the garlic and cook for a minute more.
Add the spinach to the pan by handfuls, stirring until the spinach wilts. Remove from heat and set aside.
In a large bowl, whisk together eggs, cream, salt and pepper. Add the spinach and onions and the cheese and mix well.
Pour the mixture into the prepared pan. Cook for 1 hour and 10 minutes.