Step 1

Heat the oven to 250°F with a rack in the middle position. Line a rimmed baking sheet with kitchen parchment. In a small bowl, toss together the nuts and chocolate.

Step 2

In a stand mixer fitted with the whisk attachment or in a large bowl with a hand mixer, whip the egg whites, cream of tartar and salt on medium until frothy and opaque, 1 to 2 minutes. With the mixer running, gradually add the sugar. Add the vanilla, then increase to high and beat for 5 minutes (no less, or the meringues may fall slightly during baking); the whites will be thick, shiny and hold stiff peaks. Remove the bowl from the mixer. Using a silicone spatula, fold in the orange zest and half of the nut-chocolate mixture.

Step 3

Scoop the meringue into mounds onto the prepared baking sheet, dividing it into 12 portions of about ½ cup each or 6 portions of about 1 cup each; space the mounds evenly apart. Slightly smooth the tops and sprinkle with the remaining nut-chocolate mixture.

Step 4

Bake for 1¼ hours for small meringues or 1½ hours for large meringues; they will be very pale golden brown and have expanded slightly. Turn off the oven, prop open the door with the handle of a wooden spoon and allow the meringues to fully dry and crisp, about 45 minutes.

Step 5

Remove from the oven and transfer the meringues from the baking sheet to a wire rack. Cool to room temperature.

Step 6

Meringue Cookies with Cashews, Coconut and Lime: Follow the recipe, using salted roasted cashews, replacing the chocolate chips with ¼ cup dried unsweetened wide-flake coconut and substituting an equal amount of lime zest for the orange zest.

Step 7

Golden Meringue Cookies with Pistachios and Candied Ginger: Follow the recipe, using salted roasted pistachios, replacing the chocolate chips with ¼ cup chopped candied ginger and adding 1 teaspoon ground turmeric and ½ teaspoon ground cinnamon to the egg whites along with the cream of tartar and salt.