Add the tuna and the remaining ingredients to the pot. Pour in 3 1/2 tablespoons hot water (about 50 ml) and continue cooking. Skim off any foam that forms.

Simmer on low heat until the sauce thickens and becomes glossy. Taste and adjust the seasoning to your family's preference. If using homemade fish sauce, it may be saltier than store-bought, so adjust as needed.