Heat the coconut oil in a large pot over medium heat.
Add the diced onion and stir for 3-4 minutes until translucent.
Stir in the minced garlic and grated ginger; cook for another minute.
Mix in the red curry paste and cook for 2 minutes, allowing flavors to meld.
Pour in the vegetable broth and bring the mixture to a simmer.
Stir in the coconut milk and mixed vegetables; simmer for 10 minutes.
Add soy sauce and lime juice; taste and adjust seasoning as necessary.
Prepare the dumpling dough by mixing the flour, baking powder, salt, and water in a bowl.
Drop spoonfuls of dumpling dough into the simmering soup; cover and cook for 10 minutes.
Garnish with chopped cilantro and scallions before serving.