2. Heat the oil in a large sauté pan and add onion, carrot, cumin and fennel seeds. Season with salt, cover and cook until tender.
3. Increase the heat to high and cook the mince, garlic, cinnamon, allspice and harissa, if using, for 5 minutes, breaking the meat up with a wooden spoon so there are no large pieces.
4. Add the stock and Worcestershire sauce and continue to cook over a high heat until the liquid has evaporated, stirring often. Season to taste.
5. Place the pizza bases on a lined baking tray and spread with the tomato paste and sour cream. Top with the venison, then a handful of spinach, spoonfuls of sour cream and the mozzarella.
6. Drizzle with olive oil and bake for 10 minutes until the pizza base is crisp and the top is lightly golden.
7. Top with the remaining leaves and diced tomato. Serve with extra harissa.