Boil the pasta: Fill your large pot with water and bring it to a rolling boil over high heat. Add a generous handful of salt — the water should taste like the sea. Drop in the pasta and cook for one minute less than the packet instructions suggest. You want it slightly underdone so it finishes cooking in the sauce. Before draining, scoop out about 120 ml of the starchy pasta water and set it aside. Drain the pasta in a colander.

Prep the asparagus: While the pasta boils, snap the woody ends off the asparagus. Cut the spears into 4 cm lengths, keeping the tips intact. If your spears are pencil-thin, leave them whole. Set them near the hob so you can add them quickly later.

Start the sauce: Place your large frying pan over medium heat. Add the butter and olive oil. When the butter melts and starts to sizzle gently — you will hear a soft hiss — add the minced garlic. Cook for 30 seconds until it smells fragrant but has not browned. If it starts to colour, pull the pan off the heat immediately.

Cook the asparagus: Add the asparagus pieces to the pan. Toss them in the garlicky fat and cook for 3 to 4 minutes. The spears should turn a vivid, glossy green and lose their raw crunch. You will see the tips deepen in colour first. Season with the salt and black pepper.

Build the cream sauce: Pour in the double cream and reduce the heat to low. Let it bubble gently for 2 minutes until it thickens slightly and coats the back of a spoon. Stir in the Parmesan, lemon zest, and half the lemon juice. Taste and add more lemon juice if you want a sharper finish.

Combine pasta and sauce: Tip the drained pasta into the pan. Using tongs, toss everything together for 1 minute. The sauce will look loose at first. Add the reserved pasta water a splash at a time until the sauce turns silky and clings to the pasta rather than pooling at the bottom.

Finish and rest: Turn off the heat. Stir through the chopped parsley and chilli flakes, if using. Let the pan sit for 2 minutes so the sauce thickens around the pasta. Serve immediately with extra Parmesan grated over the top.