Apr 17 2013

Storage Onions

You wouldn’t know it from this post, but we cooked with asparagus and strawberries this weekend. Saturday morning, as we were gathering our bags for the farmers’ market, we read online that Deep Roots was selling a few flats of strawberries and Viridian had their first asparagus of the season. We joked that we should race into the market, throwing elbows, to snatch up these products – products which, while rare now, will become ubiquitous in a few weeks. I clearly enjoy anything I can turn into a challenge, so when we arrived, we bee-lined towards Deep Roots to buy three containers of strawberries, and then darted across to Viridian for a pound of asparagus. Each farm had more than enough items left, but our self-created frenzy made the purchases even more exciting.

We turned the strawberries into pancakes and the asparagus into an immensely pleasing pasta inspired by a recipe from Chez Panisse Vegetables. As enjoyable as these creations were, I wasn’t surprised: you can create delicious meals from fresh ingredients simply by getting out of their way.

The more surprising meal I created from our farmers’ market bounty was this onion tart, a recipe from Deborah Madison’s latest book (more accurately encyclopedia), Vegetable Literacy. Madison, a former chef at Chez Panisse, is a prolific food writer and vegetarian recipe creator. In my own research, I’ve encountered numerous ways to organize whole ingredients. Some authors choose to group them by season, others by how they grow (tuber vs stalk), and still others by the botanical family they reside in. Madison has organized Vegetable Literacy by botanical family, but expanded the standard borders of these families. I own many books that group brussels sprouts, kohlrabi, broccoli, and cabbage together, all under the brassica family. Until now, I didn’t own a book that stretched this border to include mustard, mizuna, rutabagas, and collards. And no book I own has ever called attention to the “goosefoot” family (beets, chard, spinach).

There isn’t one definitive way to group whole ingredients together. Each author or cook should have the freedom to group ingredients in ways that make sense to their own kitchen and recipes. For example, I might choose to put spinach and collards together under the label “dark leafy greens". In Madison’s case, her families are gathered together to inspire us to visualize connections among vegetables, flowers, and herbs that we might otherwise miss, and to start to use these connections in the kitchen, whether by substituting beet greens for spinach, or by combining kale and brussels sprouts.

For Madison, onions reside in the lily family. She writes that while botanists classify onions in their own family, she’s chosen to keep onions (and asparagus) in the Liliaceae family, because “it’s arbitrary". Madison shares that this family is about beauty and odor. Each member is a monocot, meaning the plant sends a single shoot up from a bulb. The storage onions I used for this tart are the onions most frequently seen in kitchens all over the world. Storage onions are harvested in the fall, cured, and stored throughout the year. They release their sugars when cooked slowly and gently, as I did when preparing this onion tart. The three onions that began the afternoon as sharp and biting gradually yielded to the butter and herbs and turned into a collection of soft, light-brown, sweet pieces. The completed tart tasted sweet and inviting, enhanced by the interplay of the caramelized onions, the strong thyme flavor, and the buttery crust.

Though we ultimately ate the majority of this tart for dinner, unable to resist second and third helpings, it would be equally satisfying in the morning impersonating a quiche.

Onion Tart

Recipe Source: Vegetable Literacy

Serves: 4-6


The Filling
  • 1 1/2 pounds onions (3 medium)
  • 2 tablespoons butter
  • 1 teaspoon thyme leaves
  • salt & pepper
  • 3 eggs
  • 1/2 cup creme fraiche
  • 1/2 cup milk
  • 1 cup grated Gouda or Gruyere
The Crust
  • 1 cup plus 2 tablespoons whole wheat flour (or spelt)
  • 1/4 teaspoon salt
  • 6 tablespoons butter, cut into small pieces
  • 3 tablespoons ice water


  1. Cut the onions in half and peel them, and finely dice them. Melt the butter in a skillet, then add the onions, thyme, and 3/4 teaspoon salt. Cook over medium heat, stirring occasionally, for about 25 minutes. The onions will start to color after 10 minutes. When done season with pepper and taste for salt.
  2. While the onions are cooking, whisk the eggs with the creme fraiche and milk. Stir in the cooked, slightly cooled, onions and cheese.
  3. To make the crust, either combine the flour and salt in a stand mixture fitted with the paddle attachment and add the butter gradually at low speed until it’s broken into small pebble-like pieces OR mix everything by hand with a pastry cutter. Then, drizzle in the water until the dough is clumpy and damp. Form the dough into a disk or rectangle (depending on the shape of the pan you’ll use), wrap it in plastic wrap, and refrigerate for 15-20 minutes, until chilled.
  4. Heat the oven to 400ºF.
  5. Roll the dough out and drape into the tart pan. Press the dough up the sides of the pan. Place the pan on a baking sheet and pour the onion mixture into the pan, evening out the mixture. Bake for 40-50 minutes, until the surface is golden and browned in some places. Let cool before serving. Enjoy!