Lengua en Salsa Recipe - Rumba Meats

Name: Lengua en Salsa Recipe - Rumba Meats
Ingredients: 3 lb Beef Tongue (1 package Rumba); 4 cups low sodium beef stock; 1 onion, quartered, + 1 cup finely diced; 7 cloves garlic, rough chopped, divided; 1 bay leaf; 1 teaspoon peppercorns; 1 tablespoon olive oil; 1 cup green bell pepper, finely diced; 1 cup white wine; 1 (10.5-ounce) can low sodium tomato sauce; 1 teaspoon dried oregano; Kosher salt to taste; ¼ teaspoon black pepper; Fresh chopped cilantro to garnish