Peel and finely chop the onion. Trim and dice the celery. Warm 2 tsp olive oil in a pan. Add the onion and celery. Season. Cover with a circle of greaseproof paper. Cook over a low heat for 5-8 mins till they're soft but not coloured.
Measure out 1 tsp ground cumin and 1 tsp coriander seeds. Add them both to the pan. Add a pinch of cayenne (it's spicy, so add as much or as little as you'd like). Stir and cook for 1 min.
Drain the aduki beans. Rinse them. Add them to the pan. Pour in the passata. Stir to mix. Pop on the lid. Bring to the boil. Turn the heat down and simmer for 15 mins till the chilli is thick. Stir every now and then.
Trim and peel the carrots. If you have one, use a spiraliser to make fine noodles. If not, just roughly chop them.
Pop the carrot noodles or chunks into a food processor. Pulse a few times till you have fine grains. No processor? No problem, just coarsely grate your carrots.
Put the carrots in a pan with 2 tbsp cold water. Cover. Gently cook for 5 mins. Stir every so often till the carrot rice is warmed through.
Juice the mandarin. Stir the juice into the chilli. Taste and adjust the seasoning if you think it needs it. Finely chop the parsley. Stir it into the carrot rice. Serve with the aduki bean chilli.