In a large skillet, heat 1 tablespoon EVOO, 1 turn of the pan, over medium heat. Add half the onion and cook until softened, about 5 minutes. Stir in the spinach and yogurt, season with salt and pepper and simmer over low heat for 5 minutes. Transfer to a bowl and keep warm; wipe out the skillet.
In a small bowl, mix the cumin, coriander, grill seasoning, turmeric, allspice and paprika. Rub the spice mixture all over the meat and let stand for 15 minutes. In the reserved skillet, heat 2 tablespoons EVOO, 2 turns of the pan, over medium-high heat. Add the chicken and cook for 6 minutes on each side (or add the steak or lamb and cook for 5 minutes on each side for medium-rare). Transfer to a plate.
In a large pot, combine the potatoes and enough water to cover, bring to a boil and salt the water. Cook the potatoes until tender, about 12 minutes; drain.
While the potatoes cook, in a large skillet, heat the remaining 2 tablespoons EVOO, 2 turns of the pan, over medium-high heat. Add the bell pepper, remaining onion and the garlic and cook for 7 minutes. Stir in the chicken broth, chickpeas and curry paste and cook until reduced, about 5 minutes; season with salt. Stir in the chutney until dissolved, then stir in the peas. Add the potatoes and scallions.
Serve the meat with the potato salad and spinach alongside. Pass extra chutney at the table.