Place lamb in a bowl. Add grill seasoning, 2 teaspoons cumin, chili powder, coriander, oregano, cinnamon and feta crumbles. Wring the spinach dry in a kitchen towel and add to lamb. Mix the lamb and form a long 3-inch roll on a baking sheet. Coat lamb with extra-virgin olive oil and bake 20 minutes.
Place fries and lamb in oven and roast 20 minutes.
Mix yogurt, a grated clove of garlic, cucumber, the juice of 1 lemon and 1/2 teaspoon cumin. Slice and reserve the tomatoes, cucumbers and drain hot peppers, chop and reserve.
In a small sauce pot, melt butter over medium heat. Whisk in flour and cook 1 minute. Add Worcestershire sauce and whisk in stock. Season gravy with salt and pepper and reduce 5 minutes.
Soften pita over open gas flame or under broiler.
Slice lamb loaf into 1/4-inch slices. Spread yogurt on pitas and top with a 2 slices of lamb, tomatoes, cucumbers and hot peppers. Serve 2 pitas per person. Serve fries with gravy for dipping alongside.