In a large bowl, mash together the avocado, jalapeno, onion, cilantro, the juice of 2 limes, salt and pepper. Taste and season additionally if desired. Stir in almost all over the tomatoes, squeeze in the lime juice and stir in almost all of the queso fresco. Top with the leftover tomatoes, cilantro and queso fresco. Serve immedaitely with chips!