Is this a weed? ....

It's not wild garlic.

I haven't had a scrunched up knave in a long time!

knaves? Leaves

Are the flowers yellowish in colour? If so yes it is mustard garlic. If they are white, I think it is wild garlic.

If you scrunch the knaves and smell them, that will at least confirm it is garlic.

Yes it’s a weed, not a pernicious one, I get it on my allotment and pull it out as it grows quite big. Don’t know it’s name- but I recognise it.

I would pull it out unless you want to cook with it.

According to Google lens it is garlic mustard. Here is a bit about it.

Garlic mustard, also known as 'Jack-by-the-hedge', likes shady places, such as the edges of woods and hedgerows. It can grow to over a metre tall and has small white flowers that appear from April. It is a biennial plant, so takes two years to complete its lifecycle. It grows young leaves in its first season, which it keeps over winter, and then flowers in the spring of its second year.