With its stems of vibrant red, orange, yellow, pink and deep to palest green, rainbow chard is a beautiful leafy green. The abundance of fresh chard and the olive oil in the crust give this rustic tart an earthy, nutty flavor. The pat-in-pan crust makes it easy to put together. Recipe courtesy of Outstanding in the Field.
Makes 6 to 8 servings
1 3/4 cups unbleached all-purpose flour
1/2 teaspoons kosher salt
5 tablespoons unsalted butter, at room temperature
1/4 cup plus 2 tablespoons extra-virgin olive oil
1 to 3 tablespoons ice water
1 large bunch rainbow chard (about 3/4 pound)
1 sprig fresh rosemary
1 large egg yolk
1 onion, finely diced
1 clove garlic, minced
3 large eggs
1/3 cup heavy cream
3/4 cup freshly grated Parmesan or Pecorino cheese (about 2 1/2 ounces)
Freshly ground black pepper
Combine flour and 1/2 teaspoon salt in the bowl of a food processor and pulse a few times to mix. Add the butter and pulse until mixture resembles coarse breadcrumbs. Pour in 1/4 cup olive oil and pulse a few more times. Add the ice water a little at a time and pulse just until the dough begins to come together. Use your fingers to press it into the base and up the sides of a 10-inch tart pan with a removable base. Wrap loosely in plastic wrap and refrigerate for at least 1 hour.
Clean chard leaves and remove the stems, reserving them. Trim ends off the stems and discard. Cut the stems into small dice, about the same size as the onion. Cut the chard leaves in half lengthwise and then into 1-inch wide strips. Strip the rosemary leaves from their stem and coarsely chop.
Heat oven to 400 degrees.
Remove the crust from refrigerator. Bake until golden brown, 12 to 15 minutes. While crust is baking, mix the egg yolk with a pinch of salt. Remove crust from the oven and brush with egg yolk. Bake until the glaze is set, about 2 minutes. Remove crust from oven and set aside.
Reduce oven temperature to 375 degrees.
While the crust is baking, heat remaining 2 tablespoons olive oil in a heavy-bottomed deep skillet over medium-low heat. Add onion and a pinch of salt and cook, stirring occasionally, until onion is soft and translucent, about 8 minutes. Add the chard stems and chopped rosemary. Cook, stirring occasionally, for 7 to 10 minutes, until stems are tender. Clear a small space in the pan and add garlic. Cook until fragrant, about 30 seconds, then stir the garlic into the onion and chard stems. Raise the heat to medium. Stir in the chard leaves and season with salt. Cook until leaves are wilted and soft and any liquid has evaporated, 7 to 10 minutes. Remove the pan from the heat and let cool.
Beat together the eggs and cream and season with salt and pepper. Add the chard mixture and grated cheese and mix well. Scrape the filling into the prepared shell.
Bake 35 to 40 minutes, until just set. Let cool for at least 15 minutes before serving. Serve warm or at room temperature.