My only stipulation for meringues is that they be soft in the middle. Hard, chalky, dried-out meringues get no love from me.
7 large egg whites
1-1/3 cups granulated sugar
2/3 cup dark brown sugar
1/4 teaspoon ground cardamom
1/4 cup pistachios, roughly chopped
Preheat the oven to 225°F. Line two cookie sheets with parchment paper.
Place the egg whites and both of the sugars in the bowl of a stand mixer and whisk together. Put about an inch of water in a small pot and bring it to a simmer over medium heat. Reduce the heat to low, and rest the bowl on top of the pot making sure the bottom of the bowl doesn't touch the water. Stir the mixture occasionally as it heats until the sugar dissolves, about 5 minutes. Rub some of the mixture between your fingers to make sure you can't feel any sugar crystals. If you still feel some grit, you can put it back on the heat, stirring, for a few minutes longer, but you don't want the mixture to overheat. Remove the bowl from the heat before it gets too hot to touch.
Fasten the bowl back to the stand mixer. With the whisk attachment, whip the mixture on medium-high for about 8 minutes until it cools and the meringue is firm, glossy, and holds its shape when you lift up a bit with your spoon. Mix in the ground cardamom. Using a large spoon, scoop up an apple-sized amount and use another spoon to scrape it onto the lined cookie sheets. Space them an inch or two apart and sprinkle with nuts.
Bake for about 1-1/2 to 1-3/4 hours, until the meringues are crisp and dry on the outside, but still a little soft in the center. Poke your finger through the bottom of one of them to be sure they're done to your liking. They should not be brown in any way. Remove from the oven and let cool completely. Store the meringues covered at room temperature. Makes about 20.
Source: Adapted from Ottolenghi: the Cookbook by Yotam Ottolenghi