Heat oven to 190C/fan 170C/gas 5. Season the fish and spread a little butter over the flesh side of each. Put in a shallow, buttered, ovenproof dish and sprinkle with the flaked almonds, lightly pressing them on. Bake for 12-15 mins until the flesh flakes easily.
Meanwhile, make the sauce. Gently fry the shallot with a small knob of butter in a small pan. Add the stock and saffron, bring to the boil, then boil until reduced by about two-thirds. Stir in the crème fraîche and bubble for a minute or so until slightly thickened. Pour a little sauce around each portion of fish. Lovely served with tiny, buttered new potatoes and green beans, or a fresh green salad.