Add all the meatballs ingredients, ground beef, onion, recao verde, garlic, panko breadcrumbs, salt, and egg, in a glass mixing bowl.
Mix the ingredients with your hands until combined. Be gentle, and don't overwork the meat. Form the meatballs using a cookie scoop or ⅛ cup measuring cup for perfect golf-size meatballs. Place them on a lined parchment paper baking sheet. You'll get about 20 meatballs.
Heat the Dutch oven on medium. Test if it's hot enough by sprinkling water. If bubbles form, it is ready. Add the tablespoon of oil and brown the meatballs in batches. Brown about 10 at a time. Once the first batch is done, repeat with the remaining. Remove when seared entirely and set aside on a plate.
Once all the meatballs are seared, add the 1 Tablespoon of the oil in the same Dutch oven and lightly fry the sofrito onion, red bell pepper, garlic, and half culantro leaves until the garlic is fragrant for about 3 minutes.
Add the tomato sauce and the Worcestershire sauce and mix all the ingredients. Let it simmer for 2 minutes.
Add the meatballs and the chicken stock, gently mix, cover, lower the heat, and let it simmer until cooked for about 20 minutes. Stir the meatballs every so often to prevent them sticking of the sauce.
Once the time is up, garnish with remaining culantro leaves, serve over white rice or spaghetti, and enjoy!