In a medium stockpot or Dutch oven, heat the olive oil over medium heat. Add the onion and sauté until translucent, about 6 to 7 minutes. Add the ginger, carrots, and vegetable broth, and bring to a boil. Lower to a simmer; cover and cook until carrots are tender, about 15 to 20 minutes.
When the carrots are soft, carefully blend with an immersion blender (or in a blender) until the carrots are smooth. Return the carrot mixture to the pot and add the coconut milk and red curry paste. Stir until well blended. Simmer gently for 10 minutes. Add the kosher salt, then taste and adjust seasonings as desired.
Serve with chopped cilantro, lime wedges, and red pepper flakes if desired.
Notes
Slightly adapted from Easy Gourmet by Stephanie Le