Learn how to cut an onion ... then enjoy some French onion soup (2024)

Toward the end of Henrik Ibsen’s play “Peer Gynt,” a saga of the self under siege, we find Gynt deep in the forest, peeling a wild onion. He compares his many selves — cheat, shipwreck survivor, liar, prophet, betrayer, gold-digger — to the onion’s layers.

Gynt finally exclaims, “What an enormous number of layers! Are we never coming to the kernel?

“Ah,” Gynt finds, “There isn’t one! All the way into the innermost bit, it’s nothing but layers, smaller and smaller.”

Ibsen means to say that however much self-seekers peel back the layers of their selves, what they find is nothing. Not a rotten core; no core at all.

Not so quick there, Mister Ibsen. Looked at closely, the center of a real onion sports two stem buds by which, if planted, comes the second year’s growth. The core of an onion is the beginning of a new life.

Remember that at the next meeting of your support group.

How to cut an onion without crying (as much)

Those stem buds, positioned upwards from the root end, also indicate to us home cooks how best (and less tearfully) to prepare and cook the onion properly.

It matters much if you cut an onion “pole-to-pole” through both its stem and root ends versus if you cut it along its “equator” (just as with the Earth), the opposite direction by 90 degrees.

First, the tears. As a defense mechanism against nibbling pests or gnawing animals, each of an onion’s cells contains sulfur, taken up from the soil while the onion grows. The onion also makes an enzyme that, in combination with the sulfur, catalyzes it into biting sulfurous compounds. The enzyme and the sulfur mix whenever the onion’s cell membranes are broken, for example, when cut open by the edge of a chef’s knife.

Volatilized into the air around the cutting board, the sulfur-enzyme amalgam converts some of the liquid in our eyes into sulfuric acid. Ouch, we burn, we cry.

But the cells of an onion, just like those stem buds, are longer pole-to-pole than in the perpendicular direction. If an onion is cut pole-to-pole, the knife ruptures fewer cell walls than if the onion is cut radially, along its equator. Polar expeditions on an onion mean fewer (though not an absence of) tears.

Also, cutting pole-to-pole results in more uniformly sized slices, both in width and length. For certain cooking preparations using onions, such as French onion soup (our recipe here), this means more manageable and uniform cooking and browning. Burnt ends are great from beef brisket; not so much from onions.

Nothing wrong with onions sliced along their equators, just a difference. What would a burger do without its slice of red onion? Or a hot dog without dice onions from the same cut of a white onion? Well, they wouldn’t stand for those pole-to-pole slices, thank you very much.

A cook’s note about those tears: Advisories abound about preventing tears while cutting onions. What works for me is to light two candles and place one on either side of the cutting board, hence burning off many of those volatilized sulfur-enzyme fumes.

The kitchen countertop becomes a sort of altar, which occasionally is both comforting and inspiring.

Gratin of French Onion Soup

Makes 12-14 cups or 4 large or 6 medium servings. The lengthy time to cook the onions is necessary in order to achieve the deep, rich caramelization of their native sugars. Don’t stint; take the time.

Ingredients

4 pounds (5 large) yellow onions

Olive oil

4 tablespoons unsalted butter, in 4 pieces

Salt and pepper

1/2 cup dry sherry (or 1/2 cup apple juice with splash of almond extract)

2 cups water

6 cups chicken or vegetable broth (or 2 cups beef broth plus 4 cups chicken or vegetable broth for a heartier version)

6 sprigs fresh thyme, tied in kitchen twine

1 bay leaf

Solid-crumbed, crusty, rustic bread (“levain” or baguette)

1 pound Gruyère or Comté cheese, grated on the large holes of the cheese grater

Directions for French onion soup

Get the oven to 400 degrees while you prepare the onions: Cut down through the poles of each onion, down through the root end into and through the stem end. Peel each half, keeping the flesh tethered at the root end. Slice 1/4-inch thick longways, pole-to-pole, using a mandolin if you have one. Toss the slices to loosen and separate them.

Using paper toweling, generously cover with olive oil the sides and bottom of a Dutch oven or heavy casserole (one that has a tight-fitting lid, is large enough to take all the raw sliced onions, and is safe for use both on the stove and in the oven). Lay the pieces of butter on the bottom of the pan, then all the onions, then sprinkle the onions with 1 teaspoon salt and a light grinding of black pepper. Place in the oven for 1 hour, covered, rotating the pot at the 30-minute mark.

Uncover and stir the onions well, scraping the bottom of the pot, and heat in the oven for an additional 2 hours with the lid ajar, stirring the onions every 45 minutes or so and scraping the bottom and the sides of the pot to incorporate any browned onions.

Put the pot, uncovered now, on a stovetop burner at medium-high heat and cook the onions further for at least 20 minutes (turn the heat to medium if the onions begin to burn, even if slightly), stirring and scraping the sides and bottom of the pot, letting the liquid evaporate. Then, in 10-15 minute intervals and at least 3 times, deglaze the onions in the pot with 1/4 cup of the water, stirring and scraping well throughout, until the onions are rendered a thick mass that is tawny brown.

Stir in the sherry or apple juice and let it evaporate; then add the remainder of the water, the broths, and the thyme sprigs and bay leaf. Stir well, raise the heat to high, and let the soup come to a boil; then lower the heat and simmer for 30 minutes, with the pot covered or ajar (to maintain just a simmer, not a bubbling boil).

While making the soup, prepare the bread: Slice the bread, if necessary, at least 1/2-inch thick (a bit thicker is OK) and cut each slice into rounds slightly larger than the diameter of the oven-proof bowls or crocks that you will use. (Use the upturned crocks as a guide and keep the trimmed-away pieces of bread unless they are very small.) On a baking sheet lined with parchment paper, toast the rounds and the spare pieces, flipping them halfway through, until they are toasted to your liking.

Assemble the crocks: Adjust an oven rack to the top position and heat the oven to 450 degrees. Place some of the spare (not round) pieces of bread at the bottom of each crock, then a very light sprinkling of cheese, then a few healthy forkfuls of onions and enough liquid to nearly reach the rims of the crocks. Lay a bread round on each top, pushing it down a bit, then lavishly cover the round with grated cheese, even mounding it slightly.

Set the crocks on a rimmed baking sheet and heat in the oven until the cheese melts and bubbles, 10-12 minutes or so. Turn on the broiler and hit the tops of the crocks until the cheese is browned in spots. Serve piping hot.

You may reach Bill St John at [emailprotected]