Melt butter in a large saucepan over medium-low heat. Stir in sweet potato puree and 1/2 cup chicken broth. Whisk in remaining broth, ginger, curry paste, and white pepper slowly. Cook and stir until heated through, about 10 minutes.
Reduce heat to low; whisk in yogurt. Cook and stir until yogurt is heated through, 3 to 5 minutes more. Pour into a bowl; garnish with goat cheese.