Fennel and bay leaf-stuffed salmon

In reality, the "spring lamb" on sale at this time is autumn-born from sheep deliberately managed for November lambing, out of kilter, in other words, with nature's cycle. Lambing is happening now (visit Fife for proof) and these lambs won't be ready to head to the butchers until May or June. Meat sold now as early-season lamb has been semi-intensively reared – born and raised indoors, then grown fast on concentrated feeds to be ready for spring, hardly the skipping lambs we like to imagine.

For something different, try a dramatic centre-piece of fish. A whole salmon is not only accessible to home cooks (you may need to pre-order) but surprisingly simple to work with. You don't even need a fish kettle; indeed, salmon baked in tinfoil is succulent, moist and feeds a large gathering effortlessly. Served with a vivid green caper and parsley mayonnaise, it glows with joyful spring colour and makes a striking Sunday lunch.

Fennel and bay leaf-stuffed salmon, slow baked in tin foil

Serves 8-10

150g unsalted butter, at room temperature

1 whole salmon, scaled and gutted by the fishmonger, head on, 1.8-2.5kg

1 small onion, peeled and finely sliced

1 small bulb of fennel, finely sliced

3 bay leaves

1 generous sprig of thyme

Stalks from a bunch of curly-leaf parsley (See next recipe for mayonnaise)

1. Set the oven to 130˚C/gas mark 1 (see step 2). Spread a large sheet of tinfoil on a worktop then fold it back on itself to be double lined. It should be large enough to wrap around the fish like an envelope. Butter the tinfoil very generously with a third of the butter.

2. Wipe the surface of the fish all over with damp kitchen paper to remove any surface moisture then place the fish in the centre of the tinfoil. Put half of the remaining butter, the onion slices, fennel, bay leaves and thyme and parsley stalks in the centre cavity of the fish, along with some salt and pepper. Smear the last of the butter on top of the upward-facing skin. Now wrap the foil around the salmon, making a parcel which is tightly sealed but loose around the fish.

3. Place the parcel diagonally on a large baking sheet so it fits in the oven (if it's a bit long then bend the tail end upwards). Place the sheet in the centre of the oven. To bake, allow two-and-a-half hours for 1.8kg salmon. For 900g fish, allow an hour-and-a-half; give a 1.3kg fish two hours; and for a 2.25kg salmon allow three hours. The gas equivalent of 130˚C used to be gas mark 0.5, but this doesn't exist on new models. If your oven is gas, cook at gas mark 1 but reduce the cooking time by 20%.

4. You needn't do anything more to the salmon, leaving you free to attend to other aspects of the meal or do something else, but don't leave the fish longer than the calculated time or it will dry out. After the allotted time, remove it from the oven and let it stand, keeping the tinfoil parcel closed. To serve it warm, leave it to stand for 15 minutes; alternatively leave it to go completely cold and serve at room temperature.

4. Before serving, remove the skin. If you are serving it hot, do this just before taking the salmon to the table. If serving cold, remove the skin when the fish has cooled. Make a shallow slit with the tip of a knife down the length of the fish from head to tail, down the centre of the fillet, then peel away the skin in small pieces with the tip of a small knife. Also scrape away at the grey layer that sits below the skin to reveal the pink flesh. I think it is dramatic to serve the fish with the foil peeled back just enough to reveal the flesh. Then ease the fillets away from the bone, watching out for pin bones if you can.

5. Serve with the caper and parsley mayonnaise and perhaps with hot new potatoes tossed in butter, and a crisp green salad, which I like with sliced spring onions tossed with radish and avocado.

Parsley, caper and dill mayonnaise

1 very large bunch of curly-leaf parsley

80g baby spinach leaves

200ml double cream

2 eggs

1 clove of garlic, peeled and very finely chopped

1tsp English mustard powder

50ml white wine vinegar or more to taste

200ml rapeseed or groundnut oil

90ml mild olive oil

1dsstsp small gherkins

3dsstsp very small capers, chopped

5g dill

Juice of 1 lemon

1. Bring a pan of well-salted water to the boil. Pick the leaves from the parsley stalks (use the stalks for the cavity of the salmon) and blanch the leaves and spinach leaves in the boiling water for three minutes. Drain and refresh the leaves at once in iced water. Once the leaves are cold, drain and squeeze out excess water then transfer to a small pan with the cream. Bring to the boil for one minute, then transfer to the jug of a blender, processing the parsley cream to a puree. Chill until needed.

2. For the mayonnaise, place the eggs, garlic, mustard powder and vinegar in a round-bottomed mixing bowl then whisk until the eggs are thickened. Start to add the oils in a slow drizzle until incorporated then season with salt and fresh-milled black pepper. Chop the gherkins until very finely minced then stir them in along with the capers. Finally, chop the dill and stir it in, adding parsley puree to taste to give colour and flavour. Taste and add lemon juice according to taste, bearing in mind the capers and gherkins will provide acidity. This can be made the day before, which allows the flavours to develop even further. Remove the mayonnaise from the fridge 45 minutes before serving to allow it to come up to room temperature.