Bring a pot of water to a boil over high heat. While you are waiting for it to boil prep the asparagus by breaking off the woody ends (bend the spear and it should naturally break where it needs to). Chop the parsley and grate the cheese.

Once the water is boiling add the pasta add cook according to package directions (for fresh pasta it should only take about 7 minutes).

While the pasta is boiling, melt the butter in a large pan over medium heat. Add the mushrooms and toss them around. Let them cook for just a couple of minutes until the start to brown. Add the asparagus and the olive oil to the pan and toss everything around. Cook it all together, tossing frequently, until the asparagus is tender.

Once the pasta is cooked, transfer it (using a spider or large slotted spoon) from the pot to the pan. Squeeze the lemon juice over everything in the pan and give it all a good toss to ensure it's coated. Sprinkle in the parsley and toss again. Add the parmesan cheese to the pan and give everything another good toss. Sprinkle the pepper over the top and serve.