Penne and asparagus are the perfect partners for this dish. By cutting the asparagus on the bias you end up with a shape that mimics the penne.
This is also one of those pasta meals that from the time you put the water on to boil until the pasta is cooked is plenty of time to prepare the sauce.
First I sauteed the mushrooms and then added the onions. After a few minutes of onion cooking I added the sliced garlic. By this time the water is boiling and the penne is cooking. The asparagus stems go in and I use a splash of pasta water to steam them briefly. Just as the pasta is being dropped into the vegetables, I add the asparagus tips. Stir it around and add a little reserved pasta water to make a sauce with a teaspoon of olive oil.
John finishes his dish with finishing oil, toasted pine nuts, and parmesan cheese. I go more bare bones keeping it vegan with just a drizzle of good olive oil.