- A 12 oz piece of finest-quality tuna fillet
- 1 tsp sea salt
- Juice of 2 limes
- 1 small red onion, peeled and finely chopped
- 1-2 green or red chillies, finely chopped (seeds removed or not, as you prefer)
- 3 plum tomatoes, peeled, cored, and thinly sliced
- ¼ cucumber, peeled and sliced
- 1 large avocado, halved, peeled, and sliced
- 2-3 tbsp freshly chopped cilantro leaves
- 2 tbsp olive oil
- Serve with 2/3 cup sour cream
- Slice the tuna thinly and place in a large shallow serving dish. Sprinkle with salt and cover with the lime juice. Leave to marinate for 40 minutes, turning the fish over once.
- Lift out the fish (which should now look opaque from being “cooked” by the lime juice) and put on a plate. Pour the resultant juices into a small bowl.
- Return the tuna to the dish in a presentable manner. Scatter over the onion and chillies.
- Arrange the tomatoes, cucumber, and avocado over the top. Sprinkle the cilantro leaves over the surface and finish with the olive oil.
- Finally, return the collected juices to the dish using a spoon, taking particular care to fully anoint each and every piece of avocado, so preventing any discoloration.
- Cover and chill for a further 40 minutes or so before serving. Hand round a dish of sour cream at table.