Heat oil in a large nonstick skillet over medium-high heat. Add onion, bell pepper, and garlic; saute 3 minutes. Add salt, cumin, cinnamon, paprika, and pepper; saute 30 seconds. Add potato, broth, and tomato paste; bring to a boil. Cover, reduce heat, and simmer 10 minutes. Add artichoke hearts and fish; cover and cook 10 minutes or until fish flakes easily when tested with a fork, stirring occasionally. Spoon fish mixture over couscous, and sprinkle with cilantro.