Heat a thin film of canola oil in pot. Add curry paste and stir until aromatic. Add lobster stock, golden mountain sauce, fish sauce, palm sugar and sweet potato scraps to pot. Bring to a simmer, turn heat to low and simmer until sweet potato scraps are tender. Transfer to a blender (in batches if needed) and blend on high for one minute until smooth. The sweet potato should slightly thicken the broth. Season to taste with salt.