It's been a good year for blackberries in London. They're a couple of months early I think (as are the few mushrooms I've seen), but that's part of another debate.
Because they're early, I don't think people are expecting to be out picking, and I've only seen a couple of other people with their plastic containers in the woods and on the sides of paths.
But here's what I got from about 15 minutes of picking down at the end of my road.
And here's what they looked like when mixed with apples, some from our garden (again, early) and some garden rhubarb (the right time of year, I think).
Now, stew with some sugar and a little water.
Mix up flour with some margarine and more sugar and bake for 20 minutes or so.
It was bigger than it looks there (the lumps of crumble are bigger than you think) and in fact I was able to make two decent-sized crumbles that were well-received.
Living off the land! For the extras, once in a while.