Persian Baked Egg Dish (Kuku)

Ingredients

• clarified butter or vegetable oil
• 1 1/2 teaspoons kosher salt
• 1 teaspoon ground cumin
• 1/2 teaspoon ground cardamom
• 1/2 teaspoon ground cinnamon
• 1/2 teaspoon finely ground black pepper
• 1 packed cup finely chopped spinach (about 3 ounces)
• 1 medium leek, white and pale green parts only, halved lengthwise, rinsed, and thinly sliced crosswise
• 1/3 cup finely chopped italian parsley
• 1/4 cup finely chopped cilantro
• 18 large eggs