They actually have an offer on at the moment that gives your mate £30 (double normal referral) and still gives you the 50% off https://www.gousto.co.uk/my-referrals
Be aware that this is a subscription based service, so if you don't cancel/pause subscription you will be automatically charged for subsequent boxes
Have had Gousto boxes before - really nice food and easy to make. At this price it's a bit of a bargain. heat from me.
You can really piss off a mate who has told you all about the great gousto product and given you their code by using this code instead, shafting them out of a £15 friends referral credit