If you haven’t already, you might like to try some reliably foraged foods from Forager.org.uk.
Boxes are available to buy online and contain two bags: a salad bag which currently includes wild watercress, ox eye daisy, wild marjoram and sweet cicely amongst other things. The sea vegetable bag includes sea beet, sea kale, rock samphire and various other surprises. The box includes instructions on how to deal with these deliciously flavoursome things which add a new dimension to food. The boxes are £18.95 which you may think is expensive, but the contents will easily provide 12 portions of nutritious, seasonal and currently green vegetables; and you may agree that the special qualities of the produce justify the price.
Have a look at their website for more about foraging https://www.forager.org.uk/about
You can also buy Forager products from https://www.farmdrop.com/london