Heat butter gently in a small, heavy (cast iron if possible) pan. When it’s bubbling stir in crème fraiche. Gently stir until combined and steaming but not boiling. Add beaten egg yolk and stir over a low heat until combined. Stir in the Sorrel Pesto and as soon as the mixture is combined remove from heat (this will help preserve the bright green of the sorrel). Season to taste.

Poach your eggs as you like them, prepare two slices of toast. Put the eggs on the toast and spoon the warm sauce over.

For a more substantial brunchy version you could layer the eggs and sauce onto smoked salmon or smoked trout.

Heat oven to 160 degrees. Put walnut pieces onto a baking tray and when the oven is hot put them in for 10 minutes until toasted (they should be slightly browned but not burnt). While the oven is heating up, if you are infusing your own rapeseed oil then put 3 or 4 garlic cloves in a pan and pour over the rapeseed oil. Put the pan on the heat and when the oil starts to bubble around the garlic, remove from the heat and leave to infuse for 30 minutes. Alternatively, use a ready-made garlic infused rapeseed oil.

Wash sorrel and dry it well. Put all ingredients other than salt and pepper in food processor and blitz to a rough paste. Season to taste. That’s it!

Serve stirred into pasta, grains or pulses. Flavour your Eggs Benedict as in the above recipe. Use in your sandwiches in place of butter.  Dollop onto a pizza or flatbread base to add bags of flavour.