Tuna and Avocado Tartare Tostada

Tortillas:

• Canola oil, for frying
• 4 flour tortillas, cut into 2-inch by 1-inch rectangles
• Kosher salt

Avocado Butter:

• 1 ripe avocado, peeled, pitted and chopped
• 3 tablespoons fresh lime juice
• 2 teaspoons honey
• Kosher salt and freshly ground black pepper

Tartare:

• 12 ounces sushi grade tuna, finely diced
• 2 tablespoons mustard oil
• 1 tablespoon olive oil
• 2 tablespoons capers, drained
• 1 tablespoon chipotle pepper puree (from chipotles in adobo sauce)
• 3 tablespoons chopped fresh cilantro leaves
• 1/4 cup finely sliced green onion
• 1 ripe Hass avocado, peeled, pitted, and finely diced
• Kosher salt and freshly ground black pepper