Minestrone made with green vegetables (like beans, peas, and zucchini) tastes crisp and fresh. But it still should be a soup that warms the soul, so I’ve added tiny meatballs, brightened with arugula and lime, for that cozy, hearty feeling. It’s the German in me. I can’t help it.
Combine the ground beef, crushed garlic, arugula, lime zest, 1 teaspoon of salt, and a generous amount of pepper in a large bowl and mix with your hands until well combined. Form the mixture into 38 roughly 1-inch (2.5 cm) meatballs.
Heat a splash of olive oil in a large pot over medium heat. Add the garlic and sauté for 1 minute. Add a little more oil and the vegetables and sauté, stirring, for 1 minute. Add the hot vegetable broth, lime juice, and bay leaf, season to taste with salt and pepper, and bring to a boil. Add the meatballs then reduce the heat, cover, and simmer gently for 4 to 6 minutes or until the meatballs are just cooked through and the vegetables are tender. Season to taste with salt, pepper, and additional lime juice.
Divide the soup among deep bowls, sprinkle with the spring onion, and serve immediately.