Stir in the coconut milk, red curry paste, sweetener (if using), salt, pepper, turmeric, ginger, and red pepper flakes. Use an immersion blender
to puree the soup until silky and smooth. Alternatively, you can blend the soup in batches in a blender
to puree it; just use caution and let the mixture cool slightly before blending (hot liquids can often cause your blender lid to pop off while blending).