John Dory with Fennel and Coriander & Lime Salsa

Here I've served this gorgeous fish dish with well-buttered crushed new potatoes, but you could also serve it with rice, or just some good crusty brown bread.
For the salsa:

1. Combine lime, tomatoes, coriander, sugar, shallot and season to taste.  Mix well.
2. Ideally make at least 2 hours before serving and…