Cook the pasta in a large saucepan of salted boiling water according to the packet instructions until al dente.
Meanwhile, spread the asparagus out in a roasting tray, drizzle with the oil and dot with the butter. Scatter with the chillies, garlic and anchovies and cook in a preheated oven, 200°C (400°F), Gas Mark 6, for 8 minutes until tender.
Tip the asparagus mixture and all the pan juices into a bowl. Drain the pasta, add to the bowl and toss to combine. Squeeze over the lemon juice and season with salt. Serve immediately with a scattering of Parmesan shavings.