Cardamom Waffles

Name: Cardamom Waffles
Ingredients: 6 tablespoons unsalted butter, at room temperature; 1/2 teaspoon ground cardamom; 1/2 teaspoon lemon zest; 1/4 teaspoon kosher salt; 1 cup all-purpose flour; 1 teaspoon ground cardamom; 1/2 teaspoon baking powder; 1/4 teaspoon baking soda; 1/2 cup whole milk; 1/2 cup plain whole-milk yogurt; 6 tablespoons grapeseed oil; 2 large eggs, separated; 1 tablespoon sugar; Unsalted butter, for cooking; Lightly toasted and finely ground pistachios; Seasonal fruit, such as pomegranates and diced pear; Good-quality maple syrup; Fresh mint leaves