Grilled Caesar salad soup

Cyclospora resists washing and bleaching but cannot survive heat above 158 degrees Fahrenheit, rounded up to 160 to be safe, so the produce is cooked.

For grilled romaine Caesar salad, split the romaine hearts, brush the cut side with oil and grill over high direct heat, turning a couple of times, then chop and dress with your favourite Caesar dressing, grated parm and croutons.

Cut a few thick slices of sourdough bread, five ounces total, and halve the slices to handle them on the grill.

Trim the root end off a large leek, split it lengthwise through the pale green and white leaving the dark green intact, rotate 90 degrees and split again, freeing all the sheaths. Dunk in clean water a few times and drain.

Split the romaine hearts so each section keeps some core at the base, or it will be very messy.

Oil the bread and grill it over high heat, checking every couple of minutes. Oil the leek and grill it, turning every minute or so until soft and lightly charred.

Take the bread off after five minutes total, then oil the cut sides of the romaine and char them over high heat, no longer than three minutes - they are high in water and darken very quickly once they dry out.

As soon as they are cool enough to handle, chop the leek and the romaine into one inch pieces, keeping them separate, and tear the bread into pieces.

In a four-quart pot add a quart of chicken stock, all the leek and a 75 to 100 gram hunk of Parmesan rind, and bring to a simmer over medium heat.

Reduce to low and simmer 15 minutes on a timer.

Heat a 10-inch skillet over medium about a minute.

Add the anchovy oil and a tablespoon of virgin olive oil. Once it shimmers, add the bread and toss now and then, frying gently about three minutes until crispy and brown.

Scoot the bread to the sides, add the capers and cook about 30 seconds, then remove everything to a paper towel lined pan and season with black pepper. That is the garnish.

After the 15 minutes, stir in the charred romaine and a teaspoon of dried chervil and simmer another three minutes.

Kill the heat, stir in two ounces of the grilled sourdough, then press all the watercress down into the liquid, cover and wait 10 minutes.

Spoon the soup into the blender carafe, no more than two thirds up the side or it will geyser; break it into two batches if the carafe is smaller.

Lid it with the centre plug out so steam escapes, cover with a kitchen towel, and run from lowest speed up to high for exactly one minute. Turn the variable speed back to zero before switching off.

Add 10 anchovies, one tablespoon of honey, two tablespoons of lemon juice, two tablespoons of sherry vinegar, a teaspoon of kosher salt and half a teaspoon of ground white pepper.

Add half a cup of heavy cream for texture and fat, re-lid with the towel, and blend slowly up to high for two full minutes.

Serve hot from the blender, or in summer chill it in a metal bowl set into an ice bath, stirring every few minutes; it thickens as it cools.

Top with the crouton and caper melange to serve hot or cold. Like most soups it improves made a day ahead and refrigerated.

Keep all raw vegetation below cooked food in the fridge to minimise cross-contamination; one piece of raw lettuce can recontaminate it.