Land of pie and mushie peas

A shout shatters my lovely pudding and peas
Of the green mushie variety.
Pools and pools of them lapping the edge of my plate
Round and round in a sea of green
Tiny green heads bobbing up and down
Scooped up by my metallic spear angling down
Big castle of suet dumpling lies caverned
In the middle of the green sea
A beached volcano spewing out rivers of brown
Huge meaty boulders rolling slowing down
Trying to outrun the gods of the knife
Bearing down and showing no mercy
Before long the gulls are silent
No castle
No green sea
As if it had never been
All that’s left a tiny pool of green liquid on the earths crust
Unable to defend itself against a merciless god
Who brings a white rectangular messenger to soak up the last 
Remaining of a whole community
How can these things happen
How??