Drop the asparagus tips into a large saucepan of boiling salted water. Blanch for a few minutes until tender-crisp and bright green. Remove using a slotted spoon. Stir the pasta into the reserved asparagus water and cook for a few minutes until the strands fl oat to the top and are al dente.

Drain well then add the sauce to the pasta and toss (if necessary, loosen with a little more cream or stock). Top with the asparagus spears, sprinkle generously with shaved Parmesan and serve.

To make the sauce: In a saucepan over a high heat, add the cream, stock, garlic and a little seasoning and reduce until lightly thickened. Stir in the chopped watercress.