Santalia

Santalia is a type of Coconut Jam. Surprisingly, it is not mentioned in the Wikipedia entry. It is close to the Filipino matamís. Santalia is kaya without egg so it should be simpler.

Based on this picture, it is different from our Santalia in being lighter. Santalia is almost black. And in Sabah, it is usual to add durian. Tausug in Sabah and Philippines may share the same name of Santalia but not sure of their way of cooking.

https://en.m.wikipedia.org/wiki/Coconut_jam

The Matamis recepi below uses brown sugar so is darker and looks like Sanatalia.

https://youtu.be/0vmRSQn6ps4

Pialam Itum

Pialam Itum is the unique dish of Sabahan Tausug, not Tiula Itum. Tiula Itum is the unique dish of Filipino Tausug. 

Pialam Itum is the dish that my wife cooks based on the recepi of her grandmother from his father's side. A tausug sharifah, descendent of Hassan the son of prophet Muhammad. Although my side of the family is also tausug, we do not have this dish. 

I do not have any picture of this food but it is a combination of Tiula Itum and Pialam Ista from the Philippines, modified to the Malay ingredients. However, only used for a specific fish, Ikan Sembilang, Eeltail Catfish. 

https://en.m.wikipedia.org/wiki/Eeltail_catfish

Specifically this fish. WHITELIPPED EEL CATFISH / IKAN Sembilang. 

https://myseafoodmart.com/index.php?route=product/product&product_id=254

You can get the recepi for Pialam Ista below. 

https://www.angsarap.net/2021/12/03/piyalam-istah/

This recepi is typical Filipinos or recent Filipino migrants to Sabah who have not mixed with the local communities of Brunei, Javanese, and Banjarese. It uses tomato to provide the sour taste whereas we use Assam jawa.

Pialam Ista turned into Pialam Itum by mixing with burnt coconut just like Tiula Itum. This variation cannot be found in the Philippines. So Pialam Itum is the unique dish of Sabahan Tausug, not Tiula Itum. Tiula Itum is the unique dish of Filipino Tausug.