Guacamole

1 tsp onion, very finely chopped
juice of 1 lime
4 grape tomatoes, seeded and chopped
2 large avocados, cubed
sea salt to taste

Place onion in bowl, top with lime juice and allow to meld for 5 minutes.  Add tomoto and avocado.  Mash to desired consistency.  Add sea salt to taste.  Make up to 4 hours in advance.