Heat oil in a heavy bottom pot over medium heat. Add onions and sauté until translucent and fragrant, about 7 minutes. Add garlic and ginger and cook for one more minute. Stir in curry powder.

Add vegetable broth or water and split peas. Bring to a boil then reduce heat to a simmer. Cover and simmer for 10 minutes. Add sweet potatoes and continue to simmer for another 30 minutes, stirring occasionally, until the split peas are cooked all the way through.

Season with salt and pepper and serve.