Ropa Vieja Recipe:

In a large frying pan over medium-high heat, heat olive oil.  Add chopped onions and sauté until translucent.  Add garlic and stir until fragrant.  Add the tomatoes and minced Serrano chile peppers; cook approximately 3 minutes.

Add the shredded beef, beef stock, and oregano.  Salt and pepper to taste.  Continue cooking, stirring every so often, until the mixture is almost dry.  Add the cilantro (if using).

This makes an excellent filling for tacos, burritos, and making taco bowls.