Take a large bowl and add the semolina along with the paprika peppers, garlic, coriander, oil 1 tsp of salt and the black pepper. Mix well and add into it the cut sweet potatoes. Toss well so that they get well coated.
In the meantime, turn on the oven to 225°C, air circulation and rack set in the middle.
Use a very large oven proof tray and add the sweet potatoes, spread them evenly and pour on top any left oil mixture. Place in the oven and cook for 40’ while gently tossing twice throughout the cooking.
Remove from the oven to a serving dish, sprinkle with the remaining 1 tsp of coarse salt as well as the sumac.