In a medium saucepan, cover the barley with water and bring to a boil.
Cover and simmer over low heat, stirring occasionally, until the barley has split and is tender but still slightly chewy, about 45 minutes.
Drain the barley and transfer to a bowl.
Wipe out the saucepan and heat 1 1/2 tbsp of the oil in it.
Add the onion and cook over moderately low heat, stirring, until tender, about 5 minutes.
Add the tomatoes and cook over moderate heat until their juices thicken, about 4 minutes.
Add the garlic and cook until fragrant, about 2 minutes.
Add the cumin, coriander, cinnamon, cayenne and cloves and cook, stirring, until fragrant, about 3 minutes.
Add the barley and the water, cover and simmer over low heat until the flavors are nicely blended, about 4 minutes.
In a large skillet, heat the remaining 2 tbsp of oil until almost smoking.
Add the okra and cook, turning once, until browned on both sides, about 6 minutes.
Season the okra with salt and stir into the barley.
Season the barley with salt and serve hot.
Ready in 1 hour and 10 min.