In a large stock pot, add the olive oil and set the heat to medium.
Add the onion and cook, stirring frequently, until translucent, about 3-4 minutes.
Next, mix in the mushrooms and carrots. Continue to brown the veggies for 8-10 minutes until a deep brown fond forms at the bottom of the pot.
Deglaze the pot with the beef stock and water. Bring to a simmer. Mix in the beef and veggie bouillon, bay leaves, and garlic paste. Continue simmering while you make the meatballs.
For the meatballs, preheat the oven to 400 degrees F.
Mix all ingredients in a large bowl using a fork until totally homogenous. Using your hands to mix meatballs causes the fat in the meat to melt due to your body warmth. Using a fork keeps the flavorful fat within the meatball.
Use a tablespoon measurement to portion and roll out your meatballs. Remember, these are mini meatballs!
Add your meatballs to a sheet tray as you roll. Once they are all formed, bake them in a preheated oven for 25-30 minutes until browned.
Remove the meatballs from the oven and allow to cool slightly. Gently add them to the soup.
Simmer for 30 minutes for the flavors to blend.
Serve and enjoy!