Combine lime juice, soy sauce, olive oil, sesame oil in a bowl and stir to combine. Add the cilantro, green onion, cucumber and ahi tuna. Cover and refrigerate for at least 30 minutes. Carefully fold in the avocado before serving and add extra green onions if desired. Sprinkle with sesame seeds before serving.
Cut the tortillas into 6 triangles each.
Add the oil to a heavy bottom pan over high heat. Once the oil is shimmering, add a few of the tortilla triangles at a time and fry for about 1 minute on each side until they are crisp.
Remove from the oil and transfer to a paper towel. Sprinkle with a few drops of the lime juice as they cool and sprinkle with sea salt and garlic powder. Serve immediately.
If you're short on time you can definitely just use a bag of chips. But I highly recommend toasting your own!