To make pico: combine 1 red onion, diced small; 5 roma tomatoes, diced small; 1 bunch of cilantro, minced; ½ jalapeno, seeded and minced; and the juice of 1 lime. Taste and adjust seasoning with salt to taste. Season burgers with salt and pepper, and cook to desired doneness, melting the cheese on top just at the end of cooking. To build the burger, place a few slices of avocado on the bottom portion of the bun, and sprinkle lightly with salt and pepper, and then place the cooked burger on top. Add ¼ cup of pico de gallo, and add lettuce and more tomato if desired.