Gabriela Cámara's tuna tostadas recipe

Ingredients

• 200 g sashimi-grade tuna
• 94 ml soy sauce
• 32 ml orange juice
• 25 g leeks
• 250 ml vegetable oil
• 37 g mayonaise
• 8 g chipotle chile, chopped
• 0.5 tbsp chives
• 1 packet of store-bought tostadas
• 40 g sliced avocado, to serve
• 1 lime, cut into wedges