Juice the lemons and pour the juice and about half the water into a blender.
Add one cup of parsley, and blend, then add the salt or miso and blend it in.
Add another cup of parsley and blend. Add the rest, bit by bit, enough to keep the mix moving. Add the chia or linseed, blend. The pesto should be thick and moving slowly in the blender. Add a touch more water if the blender gags.
Scrape the mixture into a bowl. If it looks too watery, stir in some extra chia or linseed to take up excess moisture - it will soon swell, so avoid adding a lot; you can always stir in more later if needed. Makes about a cupful.
Spread it on sandwiches, toast, or wafers. Nice on crackers with soups and salads. Stir it into pasta, scoop a dollop onto the dinner plate with mains, or serve as a dip. It keeps well, covered, in the fridge – the lemon juice ensures it stays looking fresh and green.