Preheat oven to 400°F. Wash sweet potatoes well, pat them dry, place them on a baking sheet, and bake for 30–45 minutes, until soft when pierced with a fork. Let them cool a bit, then peel.
Heat 1–2 tablespoons of grapeseed oil in a large pot over medium heat. Add chopped onion and cabbage and cook for about 5 minutes. Stir in minced garlic, ginger, turmeric, and paprika and cook until fragrant, about 1 minute.
Add sweet potatoes, beans, salt, and water, and bring the soup to a boil. Reduce heat to medium low, cover, and simmer for about 15 minutes. Stir occasionally.
Stir in sesame seeds. Use an immersion blender or transfer to a high-speed blender to puree soup completely. Add more water if soup is too thick for your liking, and adjust seasonings accordingly.