Heat oil, add onion and garlic and cook until translucent. Don't burn!
Add sambal, lemongrass, lemon peel, cilantro. Stir over low heat.
Add coconut milk, fish sauce, sugar.
Cool before using.
Form Cakes
Combine 1+ cup sauce and shrimp dumpling mix. Mix well. Form 2" cakes. Coat with cornstarch. It is presumed these are then fried or steamed.
Notes
The serving size is just a WAG but you can still adjust the ingredient values easily by changing the number.
The amount of dumpling mix is unclear in the instructions - "1 R Shrimp Dumpling Mix." A "round" doesn't make sense here. Guidance or guesses appreciated.
It's not clear whether these cakes are fried, steamed, etc.