Translation:May I have fish, chips and peas, please?
Pysgod (singulative pysgodyn) comes from Latin piscātus, past participle of piscor (“to fish”), from piscis (“fish”). Spanish pescado ("fish that has been caught") also comes from the same root, piscātus, and is distinct from pez ("fish"), which comes from piscis instead.
Would phys imply garden peas or mushy peas in this scenario, or possibly both?
The word pys means simply 'peas'.
Here it is ...a phys because a (and) causes an aspirate mutation.