Place the ground beef, 1/2 of the cilantro, 1/2 of the chopped onion, the garlic, garlic salt, and onion powder in a bowl. Sprinkle with salt and black pepper and mix gently until combined. Form the meat mixture into golf ball-sized meatballs.
Spray a large skillet with nonstick spray and brown the meatballs carefully over medium-high heat; remove the meatballs and set aside. Meatballs can be half cook since it will be fully cook with the rest of the soup. Cook and stir the remaining onion in the same skillet over medium-low heat until translucent, about 10 minutes.
Pour the chicken broth into a large pot, and stir in the onion; add the carrots, celery, and potatoes. Bring to a boil over high heat; reduce heat and simmer until potatoes are nearly tender, about 15 minutes. Add the meatballs and the remaining cilantro; simmer for 30 minutes. Season to taste with salt and black pepper.