In a large pot, heat a splash of oil over medium heat. Add the chopped onion and garlic, cooking until softened and fragrant, about 3-5 minutes.

Toss in the cubed purple sweet potatoes, stirring for a few minutes to absorb the flavors.

Add the vegetable broth to the pot, stirring gently, and bring the mixture to a boil.

Once boiling, add the shredded red cabbage, fresh thyme, salt, and pepper, simmering for 15-20 minutes until tender.

Gently mix in the coconut milk, allowing it to heat through without boiling.

Ladle into bowls and sprinkle with black sesame seeds before serving.