Mix the ground beef, ground pork, white rice, minced onion, and eggs together in a large bowl. Form into 1 inch meatballs; set aside.
Place the tomatillos and jalapenos in a saucepan and cover with water. Bring to a boil and simmer until tomatillos have softened and begin to turn a yellow color, about 15 minutes. Drain, then transfer contents of saucepan to a blender along with the quartered onions, garlic, cilantro, green olives, and 1 cup of water. Blend until almost smooth.
Heat the oil in the saucepan used to cook the tomatillos. When hot, pour in the tomatillo sauce and bring to a boil, stirring. Pour in 3 cups of water and return to a boil. Season to taste with salt.
Stir in the meatballs. Add water, if needed, to cover completely. Simmer, covered, until meatballs are cooked through and the soup is thick, about 30 minutes.
