12 asparagus spears, trimmed
4 young carrots, peeled and sliced
1 tsp chopped fresh chervil
1 fennel bulb, trimmed and chopped
1 garlic clove, chopped
1 lemon, finely pared zest and juice
drizzle lemon oil, to serve
1 tsp chopped fresh mint
2 shallots, peeled and chopped
4 small spring onions, trimmed and sliced
1 tsp chopped fresh tarragon
Cornish sea salt and freshly ground black pepper
oil, for frying
light rapeseed oil, for cooking
400ml/14fl oz good-quality vegetable stock
100ml/3Β½fl oz double cream
2 mackerel, fins and gills cut off, scaled, gutted and pin-boned
100g/3Β½oz podded peas