Preheat your oven to 350 degrees. Lightly grease a 9-by-9-inch baking dish with nonstick cooking spray.
In a large skillet, cook the bacon until crisp. Transfer to a paper towel-lined plate. Crumble when cool. Set aside.
In the same skillet used to cook the bacon, fry the onion and beef over medium heat. Add salt and pepper to taste. Cook until the onion is translucent and the beef is no longer pink. Add the minced garlic and cook until fragrant. Stir in the cream cheese until melted and thoroughly combined.
Transfer the beef mixture to the prepared baking dish. Sprinkle the beef with the crumbled bacon pieces. Next, prepare the cheese sauce.
In a medium bowl, beat the eggs with a whisk until the yolks and whites are thoroughly combined. Add the heavy cream, shredded cheese, and yellow mustard. Mix until well blended.
Pour the sauce over the beef mixture. Then add the slices of dill pickle to the surface of the casserole. Sprinkle with shredded cheese.
Bake for 35-40 minutes or until the eggs are set and thoroughly cooked, and the cheese is golden and crispy. Serve immediately. Enjoy!