Place the rice in a small saucepan with the stock and bring to the boil. Reduce the heat, cover and simmer for 15 minutes until the rice is tender and sticky. Stir in the garlic, spices and chopped coriander.
Meanwhile, put the chickpeas in a food processor and whizz until almost smooth, but still retaining some texture. Add the cooked sticky rice to the bowl with the egg yolk and whizz together, then season with pepper.
Mix together the cornmeal or polenta and sesame seeds in a bowl. Form the chickpea mixture into walnut-sized balls and coat in the cornmeal mixture. Heat the oil in a large heavy-based frying pan and cook over a high heat for 4–5 minutes, turning occasionally, until crisp and golden.
Drain on kitchen paper and serve with sweet chilli sauce for dipping.