Steps
1. In a skillet, heat the olive oil over medium heat.
2. Add the chopped onion and garlic, sauté until translucent.
3. Stir in the cumin, paprika, coriander, and cayenne pepper; cook for 1 minute to release the spices' aroma.
4. Add the diced bell pepper and canned tomatoes, and simmer for 5 minutes.
5. Season the tuna steak with salt and pepper, then add it to the skillet.
6. Cook for 3-4 minutes on each side until the tuna is cooked to your liking.
7. Serve the tuna over a bed of couscous and spoon the sauce over the top.
8. Garnish with fresh cilantro before serving.