Why eat celeriac? Potassium!

Nobody needs to eat celeriac. It’s not an essential foodstuff. And wouldn’t we be in trouble if it were, since it’s pretty hard to find, as a rule. But right now it’s for sale at LaBonne’s in Salisbury.

Why bother to buy this knobby, fairly disgusting little root vegetable? Well, celeriac (or celery root) is actually really delicious; and if you’ve spent any time in France, a dish of celeriac remoulade will transport you back to any delightful bistro meals you might have had.

It’s also an astonishingly good source of potassium, which is good for getting rid of muscle cramps — especially for growing children, especially in the calf muscles — and for reducing hypertension. A study at Harvard showed that men with hypertension who took in 4,300 milligrams of potassium a day (food sources are considered better than supplements) reduced their risk of stroke by 38 percent.

The irony with celeriac is that it is as full of sodium as it is of potassium — sodium of course being one of the foods that people with high blood pressure generally avoid. This recipe is also fairly salt intensive, so if you’re concerned about the sodium levels, try peeling your celeriac and eating it raw, in salads or with dip.

Celeriac remoulade

Adapted from Julia Child

Makes about 4 cups

1 1-pound celery root (about 3 inches in diameter)

1 1/2 teaspoons salt (unless you’re worried about sodium)

1 1/2 teaspoons fresh lemon juice

1/4 cup Dijon mustard

3 tablespoons boiling water

1/2 cup good quality olive oil

2 to 3 tablespoons apple vinegar

Salt and freshly ground pepper to taste

Carefully cut away the knobby, root-covered peel, using a heavy, sharp knife, then cut the root into 1-inch chunks. Shred them in a food processor. Meanwhile, mix the salt and lemon juice. Immediately toss the shredded celeriac into the lemon mixture, and keep it there for about 20 minutes. The lemon will keep it from turning brown and the salt will tenderize it.

As the shredded celeriac soaks, mix the viniagrette. A basic Dijon vinaigrette would probably work fine (add some mayonnaise to thicken it up). But Child’s recipe calls for a more labor-intensive methodology: Warm a large bowl over simmering water and then put the bowl on your work surface. Add the mustard and then gradually whisk in the boiling water and then the oil and, last, the vinegar.

Remove the soaked celery root and rinse it in cold water. Drain and dry it. Fold the celery root into the dressing and season with salt and pepper. The taste will intensify if this salad is allowed to sit, refrigerated, for a few hours (or even a few days) before you serve it.