In a large cooking pot, heat a tablespoon of oil over medium-high heat. Add the beef shank and sear it on all sides until it develops a rich, golden-brown crust. This step enhances the flavor of your broth.
Once the beef is browned, pour in enough water to cover the meat completely. Bring it to a boil, then reduce the heat to a simmer. This simmering process is crucial for developing a flavorful broth.
Add chopped onion and minced garlic to the pot. These ingredients will infuse the broth with aromatic goodness. Allow them to simmer for about 10 minutes.
Gradually add your chopped carrots, potatoes, and corn. Each vegetable contributes its unique flavor and nutrients to the soup. Stir gently to combine.
Season your Caldo de Res with salt, pepper, and any additional spices you prefer. A bay leaf or a sprinkle of cumin can elevate the flavor profile. Taste and adjust the seasoning as needed.
Cover the pot and let the soup simmer for about 1.5 to 2 hours. This slow cooking allows the beef to become tender and the flavors to meld beautifully. Stir occasionally to ensure even cooking.
About 10 minutes before serving, add chopped zucchini and cilantro to the pot. These fresh ingredients will brighten the soup and add a burst of flavor.
Once the beef is tender and the vegetables are cooked, ladle the Caldo de Res into serving bowls. Garnish with lime wedges and additional cilantro for a refreshing touch.