02For the avocado butter: Combine all ingredients in a blender and blend until smooth.03For the tartare: Combine tuna, mustard oil, olive oil, capers, chipotle, cilantro, and green onion in a large bowl. Gently fold in the avocado and season with salt and pepper, to taste.04Place each of the fried tortilla pieces on a plate and spread with a small dollop of the avocado butter. Top the butter with some of the tuna tartare. Repeat with the remaining ingredients.