Step 1

Combine kingfish, onion, jalapeño, orange juice, olive oil and half the lime juice in a bowl, season to taste and refrigerate for 15 minutes to marinate.

Step 2

Meanwhile, heat vegetable oil (about 2cm deep) in a large frying pan over medium-high heat. Fry tortillas one at a time, turning once, until golden and crisp (1-2 minutes each side; be careful, hot oil will spit). Transfer to a tray lined with paper towels. Repeat with remaining tortillas. Season to taste with sea salt.

Step 3

Process avocado, sour cream and remaining lime juice in a blender or food processor until smooth and season to taste. Spread tostadas with avocado cream, top with ceviche, radish and coriander, season to taste and serve.