unidentified pest eggs

when harvesting some salad for yesterday's dinner i turned over a spinach leaf to find these eggs. well i assume they're eggs? the piccy is a bit blurry i'm afraid. they're bright green (almost fluorescent) round balls that are spiralled into a perfect hexagon shape. each ball is smaller than a pin head, the whole hexagon is smaller than a 5p coin.  it's rather stunning to find it but i am concerned that it may be an unwelcome pest. anyone know what this is?

many thanks

Some sort of butterfly/moth eggs-I wouldn't want to keep them

Almost certainly eggs of the Large White butterfly, which lays batches of 20-100 eggs (the Small White lays lots of single eggs.)  Squashing/rubbing them off is the usual method, unless you want to risk waiting to see what emerges, but bear in mind caterpillars of the Large White can defoliate a plant in mere days!