In a large mixing bowl, combine the hard-boiled eggs, shredded low moisture mozzarella, grated Parmesan, mayonnaise, Dijon mustard, minced green onions, salt, and pepper. Use a fork to smash the eggs and blend everything until uniform, about 3-4 minutes.

Using a 1/4 cup measuring cup, scoop and press the mixture into round discs, flattening them to about 1 inch thick.

Heat a non-stick skillet over medium-high heat for 2-3 minutes. Lightly coat the pan with cooking spray or a small amount of oil.

Carefully place the patties in the skillet, cooking for 1-2 minutes per side until golden brown and crispy.

Transfer cooked patties to paper towels to absorb excess oil. Serve warm on a bed of lettuce or on toasted bread.