1. Boil the rice in salted water. Wring out the capers, drain the anchovy fillets, then coarsely chop the capers together with the anchovies, spring onion, garlic, and mint. Add grated orange zest and chopped tuna, then top with orange juice.
2. Cut the bell peppers in half, remove the stalk and seeds, and submerge in boiling water for a few minutes until slightly cooked.
3. Drain the rice and leave to cool. Mix the rice with the chopped mixture previously prepared, then fill the drained and dried peppers.
4. Place them in a baking dish and cook in the oven for around 10 minutes to make the filling slightly crispy.
