If those are the fruiting bodies not Broom, its fruits resembled pea pods and peas.

Those stems certainly look like one of the Brooms, (Cytisus or Genista varieties) but the pods are nothing like the seed pods on either, which are usually much flatter , elongated and turn brown very rapidly. Not sure what it is - more photos showing the whole plant (for growth habit) might help, and did you notice any flowers at any point, what colour were they, and shape if you can remember?

It reminds me of a saltmarsh plant but I can't what.

I think it is Carmichaelia possibly C. kirkii. Images of its pods are very similar. Carmichaelia are a genus native NZ plant. also known as a NZ brooms.

you may have to have a good look to check the actual species. what is its habit? is it a climber? C kirkii is a climber/scrambler. if it is, its quite rare.

Thanks everyone, that carmichaelia identification looks right. All the pods have a sharp spine at the base which seems to be consistent.

https://en.wikipedia.org/wiki/Carmichaelia#/media/File:Carmichaelia.arborea.ripe.pod.jpg