Albondigas - Mexican Meatball Soup

Meatballs:

• 1/2 lb lean ground beef (at least 80% lean)
• 1/2 lb ground pork
• 1 egg
• 2 tablespoons uncooked long-grain rice
• 1/2 cup old-fashioned oats
• 2 plum (Roma) tomatoes, diced
• 1/2 medium onion, diced
• 2 cloves garlic, finely chopped
• 2 teaspoons salt
• 1/4 teaspoon dried Mexican oregano leaves, crushed
• Pepper, as desired

Broth:

• 10 cups water
• 1 bunch fresh cilantro
• 1 serrano chile, finely chopped
• 1 clove garlic, minced
• 2 1/2 teaspoons beef bouillon granules
• 1/2 teaspoon finely chopped fresh oregano leaves
• 3 carrots, cut into 2-inch batons
• 3 medium russet potatoes, peeled, cut into 2-inch batons
• 2 medium zucchini, cut into 2-inch batons

Garnish, as desired:

• Finely chopped fresh cilantro
• Lime wedges
• Corn tortillas