Prepare the Marinade: In a bowl, mix the yogurt, olive oil, lemon juice, garlic, onion paste, tomato paste, salt, pepper, cumin, paprika, coriander, cayenne, allspice (or cinnamon), marjoram, rosemary, and thyme until well combined.

Marinate the Meat: Rub the marinade generously over the chuck roast, ensuring it is fully coated. Place the roast in a resealable bag or covered dish and refrigerate for at least 4 hours or, preferably, overnight.

Cook the Chuck Roast: Preheat the oven to 300°F (150°C). Place the marinated chuck roast in a roasting pan or Dutch oven. Add 1/2 cup water or beef broth to the pan.

Cover tightly with a lid or foil and slow-cook for 2.5–3 hours, or until the meat is tender and easy to slice.

Slice and Crisp the Meat (Optional): Let the cooked meat rest for 10–15 minutes. Slice thinly against the grain. For crispy edges, spread the slices on a baking sheet and broil on high for 2–3 minutes until golden and slightly crisp.

Assemble: Serve the sliced meat on warm pita bread or flatbread. Add sliced tomatoes, onions, and a drizzle of garlic yogurt sauce (mix yogurt, minced garlic, olive oil, and a pinch of salt).