1. In a mixing bowl, add 1 fresh squeezed lime, half an onion diced into ½ inch slices, fresh oregano, and salt. Mix ingredients well.
2. Slice pork belly 2 inches thick.
3. Set the comal or griddle on medium, heat up tortillas of your choice for 1 minute on each side. Remove tortillas from the griddle and place on a plate. Serve your pork belly on the tortilla topped with guacamole and citrus onions.