Heat olive oil in a heavy-bottomed frying pan.
Sauté the shallot gently until soft without browning.
Add thyme, anchovy essence, wine, and fish stock then bring to a boil.
Simmer the sauce until the liquid reduces by half.
Boil a large pot of salted water.
Cook the asparagus in the boiling water for six minutes.
Drain the asparagus, reserving the water, and combine asparagus with reduced sauce and crab.
Cook the fettuccine in the reserved asparagus water for 3-4 minutes.
Drain the pasta and add it to the crab sauce.
Heat butter in a separate pan until golden brown and nutty.
Stir lemon juice and parsley into the brown butter and pour over the pasta.
Toss the ingredients together to combine well.
Season generously with black pepper before serving.