In a large bowl, combine thoroughly both beans, tomatoes, onion, cucumber and corn.
In a small bowl, whisk together the lime juice and olive oil. Season with sea salt to your taste.
Add dressing to the bean mixture. Gently and thoroughly combine (I mix it gently with my hands).
Taste test for seasoning. Need more Lime juice? Salt?
Stir in the chopped cilantro.
Place the bean mixture in your serving dish of choice.
Arrange avocado pieces on top.
Serve with tortilla chips.