Halve, slice, wash the leeks well and drain
. Heat the oil in a skillet over medium heat. Add the leeks and cook until softened but not brown, about 5 minutes. Add the peas and continue cooking until the peas
are thawed and bright green, about 3 minutes. Transfer the peas and leeks
to a blender
along with the sour cream, salt, parsley, and lemon
. Blend on low until smooth. Garnish
with the scallions.