Heat the olive oil in a large pan over medium heat. Add the chopped onion and garlic and sauté until softened.
Add the diced sweet potato and baby tomatoes to the pan.
Sprinkle in the oregano, cumin seeds, coriander seeds and smoked paprika. Stir well to coat the vegetables in the spices.
Pour in the vegetable stock and simmer for about 10 minutes, or until the sweet potato begins to soften.
Add the grated courgette and black beans. Continue cooking for another 10 minutes, or until all the vegetables are tender and the mixture has thickened.
Stir in the cooked rice and heat through.
Taste and season with salt and pepper as needed.
Serve warm, topped with chopped fresh coriander.