Cook the pasta in plenty of salted boiling water for about 10 minutes until just tender. Drain and return to the pan.
Meanwhile, scatter the asparagus in a shallow roasting tin. Dot with the butter and season lightly. Place on the upper rack of the halogen oven.
Set the temperature to 250°C (482°F) and cook the asparagus for about 5 minutes until just tender. (The time will depend on the thickness of the spears.)
Put the asparagus, sun-dried tomatoes, the 3 tablespoons olive oil and pastrami in the pan with the pasta. Sprinkle over the lemon juice and season with salt and pepper. Mix well and turn into a shallow ovenproof dish. Place on the lower rack of the halogen oven.
Set the temperature to 200°C (392°F) and cook for 5 minutes to heat through. Serve scattered with Parmesan shavings.