In a mixing bowl, combine all ingredient for the meatballs and mix until all evenly combined.
Preheat a large pot over medium heat and add olive oil. Form small meatballs and add them to the pot. Cook meatballs over medium heat until about half way done.
Add diced onion and minced garlic. Saute for a couple of minutes.
Slowly add stock and raise heat to medium-high. Bring it to boil and lower the heat back to medium.
Add salt and red pepper flakes to taste.
Add orzo and chopped kale. Cook until orzo is done.
Whisk egg in a small bowl and mix it with fresh grated Parmesan cheese.
Once orzo is cooked, start slowly swirling soup (in one direction) and slowly pour in the egg mixture.