How much of the mushrooms do I need for this recipe?

Here is a link to the recipe posted in the recipe author's blog: https://www.veganosity.com/pasta-with-peas-portobellos-and-walnuts-in-an-aglio-et-olio-sauce/. As BB says, it lists 20 mushroom caps. It appears that the recipe as posted on F52 is incomplete.

In similar recipes, I see equal weights of pasta and mushrooms...that would be 1 lb here.
But/And agree with BerryBaby.
Use as many mushrooms as you have on hand or to taste.

I read the recipe and it calls for 20 medium portabella mushroom caps. Unless they are sliced, it’s hard to measure in a cup. There are about 10 in the prepackaged containers. Honestly, you could do less or more mushrooms depending on your preference.