Spinach and Three Cheese Phyllo Pie

Name: Spinach and Three Cheese Phyllo Pie
Ingredients: Nonstick cooking spray or butter, for the baking dish; 1/2 cup pine nuts; 2 tablespoons (1/4 stick) unsalted butter; 1 tablespoon olive oil; 2 yellow onions, diced; 2 garlic cloves, minced; Three 20-ounce bags frozen chopped spinach, thawed and squeezed of excess water; 4 extra-large eggs, lightly beaten; 2 cups crumbled feta cheese; 1 cup ricotta cheese; 1/2 cup grated Parmesan cheese; 1 tablespoon freshly ground black pepper; 2 teaspoons kosher salt; Pinch nutmeg; 8 sheets frozen phyllo dough, thawed; 3 tablespoon unsalted butter, melted; 2 teaspoons za'atar (if you can't find za'atar, use sesame seeds)