Heat an ovenproof large skillet coated in cooking spray over medium-low heat and turn the broiler on in your oven.
Crack an egg into a bowl, add the milk, and whisk until well blended; season with sea salt and freshly cracked pepper, to taste.
Pour the egg mixture into the skillet and swirl so the pan is evenly coated with the egg.
Once your egg starts to set, immediately remove it from the heat, and sprinkle half of it with the ground beef mixture, tomatoes, avocado, green onion, olives, and shredded cheese.
Move the ovenproof large skillet to the top rack of the oven, and broil the top part of the egg until set, which takes only 20-30 seconds or so.
Remove the skillet and flip the other part of the egg mixture on top of the ground beef mixture.
Slide onto a plate and serve immediately with salsa on the side if desired. Enjoy.