Interesting! It looks like a Peziza sp. (a cup fungus) but not one I'm familiar with. It is likely associated with your region of the world but not mine. The British Mycological Society is very active: If you contact your local club within the Society I expect they will be able to narrow it down to species. cheers, frog
Agree Peziza sp.; perhaps Peziza vesiculosa or Peziza repanda. Whichever it is, looks very dried out! And also harmless to your vegetables.