Heat the olive oil in a heavy-bottomed frying pan. Add the fennel seeds, chilli, shallots, parsley stalks, lemon zest and seasoning, and fry for about 5 mins, or until softened and aromatic. Add the tomato purée, cook for a couple of mins, then deglaze with the vermouth. Add half the crabmeat, stir to create a thick sauce, then remove from the heat while you cook the pasta.

Bring a large pan of salted water to the boil and cook the pasta until al dente. With 3 mins remaining, add the asparagus, then use a slotted spoon to transfer the pasta and asparagus to the crab pan. Put the crab pan back on the heat, add a couple of spoonfuls of pasta water to loosen and toss together, coating the pasta in the sauce. Add the rest of the crabmeat, crème fraîche and lemon juice, and warm through. Divide between plates and garnish with parsley, chives and hazelnuts.