Preheat the oven to 350 degrees F. Spray an 8x8 baking dish with cooking spray.
In a large skillet over medium heat, cook ground beef, onion, and garlic until the beef is browned. Season with salt and pepper. Drain any excess fat.
Whisk the eggs in a bowl and stir in the unsweetened almond milk.
Spread the beef mixture evenly into the prepared baking dish. Pour the egg mixture evenly over the top.
Sprinkle the cheddar cheese over the casserole.
Cook uncovered for 20-25 minutes, or until the casserole is set and the cheese is bubbly and golden.
Top with diced tomato and pickle.