Cheese Fatayer — Middle Eastern cheese pockets

Ingredients

• 2 cups all-purpose flour
• 1 teaspoon instant dry yeast
• 1 teaspoon granulated sugar
• 1/2 teaspoon fine salt
• 2 tablespoons olive oil
• 3/4 cup warm milk, more as needed
• 7 ounces feta cheese, crumbled
• 3 ounces mozzarella cheese, shredded
• 2 tablespoons fresh parsley, finely chopped
• 1/2 teaspoon nigella seeds or black sesame seeds (optional)
• 1 egg white
• Freshly ground black pepper, to taste
• 1 egg yolk
• 1 tablespoon milk or water