Meanwhile, heat 2 tbsp of the coconut oil in a large pan over medium heat
Add the bell peppers and chiles along with a pinch of salt.
Cook, stirring occasionally, until softened, 15 to 18 minutes.
Transfer peppers and chiles to a food processor and set aside.
Put the remaining 1 tablespoon of coconut oil in the same pan and set over medium heat.
Add the shallots and a pinch of salt, and cook, stirring often, until they turn a deep golden brown, about 10 minutes.
After about 8 minutes, add the garlic to the shallots and cook for 1-2m minutes
Add shallots to the food processor along with the tomato; process into a smooth purée.
Transfer the sambal purée back to the same pan, adding the sugar, lemongrass, galangal and lime leaves.
Cook over low heat, stirring occasionally, until the oil starts to separate and the sambal has thickened and turned a deep red, about 30 minutes.
Stir the shrimp and cooked potatoes into the sambal; cover and cook until the shrimp are just cooked through, about 10 minutes.
Before serving, remove the lemongrass, galangal, and lime leaves.
Serve immediately, or at room temperature with a side of rice.