Sift the flour into a bowl; beat together the egg, oil and milk and stir into the flour. Mix all the ingredients to form a soft dough; turn the mixture out onto a floured board and knead lightly shaping into a ball, and refrigerate for 10 minutes.
Heat the oil in a medium-sized non-stick pan, sauté the onions and garlic until they have just softened, then add the ground beef (or lamb or chicken) and cook for 3-4 minutes or until it is lightly browned; stir in the pinenuts, tomato paste, cumin, sumac, cinnamon and baby spinach leaves, and cook gently for another minute or two, or until the baby spinach leaves have just wilted, then set aside.
Cut the pastry dough into 4 equal portions and roll out each portion into 30cm x 17cm ovals; spoon the filling over the pastry leaving a 21/2 cm edge.
Fold the pastry edges over the edges of the filling leaving most of the filling exposed; and seal by twisting the pastry ends; brush the pastry with beaten egg and carefully place the pizzas onto a lightly greased baking tray.
Bake the pizzas in a preheated oven at 200°C/400°F for 12-15 minutes or until they are golden brown.
Serve the pizzas with dollop of tzatziki.
NOTES: Because something in tomato paste disagrees with me, when I've made these, I've used a well-drained can of tomatoes and added an Australian bush tomato spice which has a very tomatoey taste; and I've also added a teaspoon of lemon juice.