Set a pot of well salted water to boil. Trim the bottoms off the asparagus and, if they are thick, peel off their skins from just below their tips downwards.
When the water comes to a boil, add the asparagus and cook until fully tender. Remove the asparagus from the water with a skimmer or tongs. (Don't drain the water out of the pot.) Let the asparagus cool then cut the tips of the asparagus into short lengths.
Put the rest of the stalks into a blender, along with a good knob of butter, a basil leaf or two, a spring of parsley, a pinch of salt and a ladleful of the water in which the asparagus have boiled. Blend well, adding more water if needed to obtain a smooth, pourable purée. Taste and adjust for seasoning.
Meanwhile, defrost the frozen artichoke hearts under warm water, then drain and cut them into thin wedges. Combine with the peas and asparagus tips in a bowl and have this medley at the ready.
Now add the fusilli to the pot where you've cooked your asparagus and cook until al dente.
While the pasta is cooking, warm a good pour of olive oil and a knob of butter in a large skillet. Add the pancetta and let it render, then add the spring onion and sauté just until it wilts. Add the artichokes, peas and asparagus tips. Sauté everything together over lively heat for a few minutes, seasoning with salt and pepper and moistening with a drizzle of white wine as you go.
When the vegetables are tender and have had a chance to absorb the flavors of the onion and pancetta, remove about half the vegetable mixture and set aside.
Add the asparagus purée to the skillet with the remaining vegetables, mix well and set over very low heat.
Mix the egg and grated cheese together in a bowl and reserve.
When the pasta is almost, but not quite al dente, drain and add to the skillet. Toss the pasta with the sautéed vegetables over low heat, loosening the pasta with a ladleful of the pasta water if need be. Keep tossing for a minute or two, until the pasta is well coated, then add the egg and cheese mixture, and mix it in well, allowing the sauce to thicken slightly, as if making a carbonara.
Serve the fusilli immediately, topped with the rest of the sautéed vegetables, along with additional grated Parmesan on the side for those who want it.
