Preheat oven to 350º
In a skillet over medium heat cook bacon until crispy. Remove bacon from skillet and drain excess grease from pan.
Return skillet to heat and add onions into skillet. Cook until tender and set aside. Add spinach to skillet and cook until wilted; about five minutes.
In a large bowl whisk together six eggs. Add two cups cream and whisk until well combined. Add in cheese, onions, bacon. Stir until well mixed.
Transfer mixture to a skillet or pie plate that’s been prepared with nonstick cooking spray. Bake at 350º for 30-45 minutes, until the edges are lightly browned and the middle is set.