I usually get some fennel, slice thinly and place on the bottom of a baking tray with some olive oil, salt, pepper, dill, and white wine. Season the fish, stuff the fish with lemon slices, more fennel, chilli (optional) and cover with foil. Bake for 20 mins at 170 and remove the foil and bake for a further 5 mins.
Sauce vierge is lovely with most fish.
50 g shallots, finely chopped
100 g skinned, seeded and finely diced tomatoes (I use cherry tomatoes or baby plum tomatoes)
150 ml extra virgin olive oil
Juice of 1 lemon
1 tbsp capers, drained
1 tbsp chopped fresh parsley
1 tbsp chopped fresh basil
Put the shallots, tomatoes and olive oil in a saucepan, season with salt and pepper, and gently heat for 2 minutes. Keep warm. Add the lemon juice, capers and chopped herbs before serving.