I might have a crack at it. I love spinach. I see the recipe says 180g of cooked spinach. As we all know, spinach wilts spectacularly once cooked. Do we think that would equate to 500g of raw baby spinach leaves, wilted and very well drained? If using frozen spinach, I might see if 300g would produce 180g cooked spinach. Poor recipe writing not to give this detail.
I do like broad beans and will make the effort to take off the skins, as they are much nicer that way. Would definitely use frozen. I've never had the good luck to eat them freshly picked but frozen are much better than the ones I can buy fresh, as I am a long way from any farm shop.