1. Preheat oven to 350F
2. Heat a large skillet over medium low heat. Add bacon and render until crisp. Drain on a paper towel-lined baking sheet and set aside.
3. To the bacon fat in the pan, add the shallot and mushrooms and cook until softened/ browned. Add to the bacon.
4. Whisk the eggs, milk, and salt and pepper to taste in a large bowl.
5. Add the bread, 1 1/2 cups of the cheese and the bacon/shallot/mushroom mixture to the egg mixture. Mix well. Cover and refrigerate for at least 30 minutes or overnight.
7. Grease a 9x13 baking dish with butter. Pour the strata mixture into the pan and top with remaining ½ cup cheese.
8. Cover with foil and bake for 25 minutes, then remove foil and bake for another 15-20 minutes until golden and a skewer inserted into the middle comes out clean.
9. Allow to rest for 5 minutes, sprinkle with parsley, and serve!