In a large mixing bowl, combine ground beef, panko breadcrumbs, egg, 2 cloves minced garlic, ½ teaspoon cumin, salt, and pepper. Mix gently with your hands until just combined—avoid overworking the mixture.

Roll the mixture into 1½-inch meatballs and set aside on a plate lined with parchment paper. You should have approximately 16–20 meatballs.

Heat olive oil in a large pot or Dutch oven over medium-high heat. Once shimmering, carefully add the meatballs in a single layer and brown them for 3–4 minutes per side until golden. Work in batches if necessary. Remove and set aside.

In the same pot, add diced onion and remaining 2 cloves minced garlic. Sauté for 2–3 minutes until fragrant and the onion begins to soften.

Add chipotle peppers, adobo sauce, and remaining ½ teaspoon cumin to the pot. Stir well, cooking for 1 minute to toast the spices.

Pour in the beef or chicken broth and diced canned tomatoes with their juices. Stir to combine.

Return the meatballs to the pot along with diced potatoes. Bring the soup to a boil, then reduce heat and simmer for 15–20 minutes until the potatoes are tender and the meatballs are cooked through.

Taste and adjust seasoning with salt, pepper, and lime juice. Stir in fresh cilantro just before serving.

Serve hot with lime wedges, additional cilantro, and crusty bread for dipping.