In a food processor combine the tomatoes, the garlic, one jalapeño, half the cilantro, and the lime juice.
Pulse a few times and season to taste. Set the salsa aside.
In a skillet placed over a medium heat, fry the onion and the other jalapeño with some coconut oil until soft (about 4 minutes).
Add the crab to the skillet and cook until warm (about 2 minutes).
In a bowl or separate plates, top lettuce with the crab meat, avocado, green onions, and remaining cilantro.