Cook the rice in 300 ml boiling salted water for about 20 minutes. Clean and wash spring onions and cut into rings. Wash the chilli, cut lengthwise, remove seeds and also cut into rings.
Drain the tuna. Add spring onions and chilli rings to the rice about 5 minutes before the end of the cooking time and cook along with the rice. Fold in tuna and cheese. Wash the peppers, cut off one lid each and clean the pods.
Fill the rice mixture into the peppers, place the lid on top and braise in hot fat in a wide pot. Pour on the stock and cook covered for 20-25 minutes.