Local organically grown sorrell from Moss Valley Market Garden just outside Sheffield.
As fresh as you can get without growing your own.
Here's what one source says about sorrell:
"a leafy green plant, use alternately as an herb and a vegetable, with a distinctive sour, lemony flavor.
Sorrel falls straight between herbs and greens. Use it as a leafy herb, like parsley or basil or mint, chopping it up to use in marinades and dressings, or stirring it into soups or casseroles for a bit of fresh flavor. Or, use it as a green, ripping the tender leaves into salads and stir-fries.
The tart and bright flavor of sorrel make it particularly good at adding some life to potatoes, eggs, and whole grains. It is also delicious with smoked or oily fish like salmon or mackerel. Sorrel is classically paired with cream, sour cream, or yogurt. This adds a vibrant green color and tartness to these plain items as their fatty creaminess tames the sharp flavor of the sorrel.
Sorrel is also a great addition to other cooked greens. Add a handful or two when you cook spinach, chard, or kale for a lovely sour kick."
https://www.thespruceeats.com/all-about-sorrel-4102185
