help identifying

havadayoff

Can anyone tell me how to tell the difference between red veined dock and chard as I have two plants that have appeared one in one of my pots on the kitchen window sill which has coriander in but is next to another pot which I sowed with mixed herbs but then the same plant has appeared in my back garden but I'm not sure whether it is red veined dock or chard.

Welshonion

Try eating a bit and you will soon know the difference.  Usually chard has wider stems when it is older.