Stir 2 teaspoons chicken broth, white onion, and garlic together in a pot over medium-high heat; cook until the onion is tender, about 5 minutes. Pour remaining chicken broth into the pot; bring to a soft boil. Add meatballs, garbanzo beans, kidney beans, mixed vegetables, pasta shells, ground ginger, oregano, basil, and cilantro; season with salt and pepper. Stirring occasionally, bring soup to a boil. Reduce heat to medium-low, cover the pot, and cook at a simmer until the pasta shells are tender and meatballs are heated through, 12 to 15 minutes.