Heat olive oil in a large pot over medium heat. Add onion and garlic, cooking for 2–3 minutes until softened.
Add diced sweet potato and sauté for 5 minutes.
Stir in kidney beans, chopped tomatoes, tomato paste, vegetable broth, and spices. Mix well.
Bring to a boil, then reduce heat and simmer for 30–35 minutes, stirring occasionally, until sweet potato is tender and the chilli has thickened.
Taste and adjust seasoning as needed. Serve hot over rice, baked potatoes, or enjoy straight from the bowl.