Peel and finely chop the red onions. Peel and finely dice the carrots. Peel and grate or crush the garlic. Warm a large pan on a medium heat for 2 mins. Add 2 tbsp oil, the onions and carrots. Season with salt and pepper. Cook for 8 mins, stirring now and then, till the veg soften and pick up some colour.
While the veg cook, peel and chop the sweet potatoes into 2-3cm chunks. Finely chop the rosemary leaves. Finely chop the chilli, flicking out the seeds for less heat – or leave the chilli out completely if you prefer a milder dish.
When the onions and carrots have cooked for 8 mins, add the garlic, rosemary, chilli and 2 tsp cumin seeds to the pan. Cook for 2 mins, stirring. Fill and boil your kettle.
Add the sweet potatoes to the pan. Tip in the tin of mixed beans, including the liquid from the tin. Pour in the tin of chopped tomatoes, along with 100ml hot water from the kettle. Add a good pinch of salt and pepper, then pop on a lid and cook for 15 mins. Stir every now and then, adding a splash more water if the chilli looks too dry or thick.
While the chilli cooks, finely shred the kale leaves, discarding any really tough or dry stalks. Grate the zest from the lime.
After 15 mins, add the kale to the pan and gently stir to mix. Cook for 3-4 mins till the kale has softened. Add the lime zest and squeeze the juice. Taste and add more salt or pepper if needed. Spoon the chilli into warm bowls and serve.