300ml double cream
30g wild garlic
Coarse sea salt
Pour the cream into a stand mixer and whisk for roughly 5-8 minutes on a medium to fast speed. You will know when it's done when the cream separates and the butter clumps together.
While the butter is churning, finely chop the wild garlic.
When the butter has separated, take a thin, clean piece of cloth or tea towel, I don’t expect many people keep cheese cloth at home, and squeeze the moisture back into the mixing bowl with the rest of the liquid and set aside.
Place some greese proof paper on a surface and roll the butter out thinly. Finely chop the wild garlic and scatter over the butter along with a good pinch of salt, then roll up and form into a ball. Repeat this process again with the remaining wild garlic, adding less if you do not want it too strong, then another pinch of salt depending on how salty you like your butter.
I also don’t expect may people have butter paddles so tapping the sides into shape while covered by some greese proof paper should do the job.
An alternative to using a stand mixer is of course a whisk! This will however leave you quite exhausted by the end. Another way is in fact to put the cream into a large empty jar with a sealed lid and shake it like you're making a cocktail until it separates.
Shake it up
The liquid that is separated from the butter in the churning process is buttermilk. Not the same as shop bought buttermilk, used in baking, which is cultured milk that is often thinckened and made more tart though cerntain processes.