Egyptian Spinach Pie with Hazelnut Dukkah

Name: Egyptian Spinach Pie with Hazelnut Dukkah
Ingredients: 1/4 cup hazelnuts; 1 tablespoon coriander seeds; 2 teaspoons cumin seeds; 2 tablespoons sesame seeds; 4 cloves garlic, minced; 4 medium shallots, finely diced; 4 tablespoons (1/2 stick) unsalted butter; 4 pounds fresh spinach leaves (not baby), stemmed and sliced; 1/4 cup minced fresh dill; Pinch freshly grated nutmeg; Salt and pepper; 8 ounces freshly grated Cheddar; 8 ounces freshly grated mozzarella; 1 package puff pastry (2 sheets); 1 large egg, beaten with 1 tablespoon water, for egg wash; 1 tablespoon sumac