Trim fat and slice the Pork Shoulder into thin strips for quick, even cooking.
In a bowl combine the sliced pork with 2–3 tablespoons of Olive Oil, 1 tablespoon Red Wine Vinegar, 2–3 smashed cloves of Garlic, 1–2 teaspoons Dried Oregano, 1 teaspoon Sweet Paprika, 1/2 teaspoon Ground Cumin, and salt and Black Pepper to taste; mix thoroughly, cover, and refrigerate for at least 1 hour (or overnight) to marinate.
Preheat the oven to 425°F (220°C). Toss the Potatoes with a little Olive Oil and Salt and spread on a baking sheet; roast until golden and crisp, about 25–35 minutes, turning once.
Heat a large skillet or grill pan over high heat, add a splash of Olive Oil, then cook the marinated pork in batches so it browns and gets slightly charred at the edges, about 4–6 minutes per batch; remove and keep warm.
While the pork cooks, make the tzatziki: grate and squeeze excess water from the Cucumber, then stir into Greek Yogurt with a minced clove of Garlic, a drizzle of Olive Oil, a splash of Red Wine Vinegar and Salt to taste; chill briefly so the flavors meld.
Warm the Greek Pita Bread briefly in a hot skillet or wrapped in foil in the oven until pliable.
Slice the Tomatoes and thinly slice the Red Onion.
Assemble each pita by spreading a generous spoonful of tzatziki, piling on the sliced pork and some roasted potatoes, then topping with Tomatoes, Red Onion, a drizzle of Olive Oil and a pinch of Dried Oregano.
Serve immediately while hot, with extra tzatziki on the side for dipping.
