Yield: about 2.5 cups, plenty for garnishing 4 plates
3cupsof shucked english peasfrozen can be easily substituted
1tbspchopped fresh mint
1cupvegetablefish, or chicken broth
1/2cupgrapeseed or canola oil
Pinchof sugar or honeyto taste
Saltfor seasoning the blanching water
Bring a pot of lightly salted water to a boil. Add the peas and cook for 2 minutes. Remove the peas and refresh in ice water to preserve their color. Transfer the peas, mint and sugar to a high speed blender. Add the stock or fish broth and puree. The puree will be chunky and coarse. Add the oil slowly, drizzling in a thin stream as if making homemade mayonnaise or aioli.
When all the oil has been added, the puree should be smooth and loose, if it isn't, add some cold water a tbsp at a time until the mixture loosens and looks smooth. Afterwords, ladle the puree into a chinois strainer and pass through using a ladle or spoon. (Passing through the strainer, while optional, is preferable and gives a smoother texture.) Double check the seasoning, it should be just slightly sweet, adjust if necessary, then reserve the puree until needed.
English peas are the best for this, but they are expensive. I have worked at restaurants that used frozen instead, which makes it way cheaper. On a related note: for some reason pea puree ferments and goes bad pretty quick, I don't know why. It's best to make this the night before or the day of serving. It will keep for 3 days in the fridge.