Gently soften the diced onion in the sunflower oil in a big pan or casserole.
Meanwhile, whizz together the roughly chopped onion, ginger, coriander stalks and jerk seasoning with a hand-held blender.
Add to the softened onion and fry until fragrant. Stir in the thyme, chopped tomatoes, vinegar, sugar and stock cubes with 600ml water and bring to a simmer.
Simmer for 10 mins, then drop in the sweet potatoes and simmer for 10 mins more.
Stir in the beans, peppers and some seasoning, and simmer for another 5 mins until the potatoes are almost tender.
Cool and chill for up to 2 days.
To serve, gently heat through on the hob.
Roughly chop most of the coriander leaves and stir in, then serve scattered with the remaining leaves.