Fill your kettle and boil it. Peel, halve and finely chop the onion. Place a medium pan on a medium-high heat and add ½ tbsp oil and the chopped onion. Season with a pinch of salt and pepper. Fry, stirring often, for 5 mins till the onion starts to soften and just pick up some colour.

Meanwhile, tip the bulgar wheat into a heatproof bowl and pour in 300ml boiling water from the kettle. Swirl with a fork, cover the bowl with a plate and set aside to soak for 10-12 mins. The bulgar will absorb the water and become tender.

Roughly chop the tomatoes. When the onion has fried for 5 mins, add the chopped tomatoes. Cook, stirring often, for 4 mins till the tomatoes start to soften and become pulpy.

While the tomatoes fry, finely grate the zest from both the limes. Finely chop the chilli (flicking out the seeds and white pith for less heat). Stir the zest and chilli into the veg with 1 tbsp Cajun seasoning. Fry, stirring, for 1 min till the pan smells aromatic.

Tip in the butter beans with the liquid from their tins. Pop a lid on the pan (or use a baking tray if you don't have a lid) and bring to a bubble, then boil for 5 mins. Stir now and then. The stew should thicken up a little and the beans will be tender but still have a little bite to them.

Squeeze in the juice from 1 lime. Taste the stew and add a pinch more salt or pepper if you think it needs it. Drain any excess water off the bulgar wheat and divide it between 2 warm bowls. Ladle over the stew and serve with the wedges of the remaining lime for squeezing.