Tip the rice into a bowl and cover with cold water. Whisk for 2 mins (you can use a fork) till the water goes cloudy. Drain the rice, tip it into a small pan and add a pinch of salt. Cover, bring to the boil and then turn the hat right down. Very gently simmer for 25 mins till the water has been absorbed. Take the rice off the heat and leave it to steam in the pan, lid on, for 5-10 mins.
While the rice simmers, peel and finely chop the onion. Put a pan on a medium heat for 1 min. Add ½ tbsp olive oil and add the onion with a pinch of salt and pepper. Cook, stirring every so often, for 5 mins.
While the onion cooks, halve the pepper and scoop out the seeds and white pith. Chop it. Chop the tomatoes to match. Trim the dry ends off the celery and finely chop it. Add them all to the onion. Cook, stirring now and then, for 5 mins till the veg start to look glossy.
Peel and grate or crush the garlic. Halve the chilli, scoop out the seeds and white pith. Finely chop it. Finely chop the coriander stalks (keep the leaves to one side for later).
Stir the garlic and chilli into the pan. Add 1 tsp each ground cumin, smoked paprika and dried oregano. Cook and stir for 1 min till the pan smells aromatic.
Crumble the stock cube into the pan. Drain the butter beans and the cannellini beans and add them to the pan. Pour in 250ml boiling water. Cover, turn up the heat and bring to the boil. Once the chilli is boiling, turn the heat down a little and simmer for 15 mins till the beans are tender.
Roughly chop the coriander leaves. Taste the chilli and add a pinch more salt and pepper if you think it needs it.
Fluff the rice with a fork and spoon into a bowl. Ladle the chilli over the top. Garnish with the chopped coriander and sprinkle over a little smoked paprika to serve.