Blacken the whole garlic and the onion
slices on all sides in a large, dry non-stick
frying pan. Remove, cool briefly, then
peel the garlic cloves. Soak the ancho
chilli in boiling water for 15 mins, drain,
then place in a blender with the sugar,
cider vinegar, garlic, onion and some salt
and pepper. Whizz to a smooth sauce.
Heat the grill. Brush each salmon fillet
liberally with the sauce and save any
remaining. Grill for 8 mins. Meanwhile,
mix the limezest with the crème fraîche.
Serve the fish with extra chilli sauce,
a dollop of the crème fraîche and lime
wedges for squeezing over. Sprinkle with
coriander, if you like, and serve with
green beans or rice and a salad.