Preheat the oven to 200°C/gas mark 6.
Pour the tomatoes into a large bowl and break apart using a pair of kitchen scissors or your finger tips. Add the courgettes, mint, cheese, olive oil, garlic, salt, and pepper. Stir to combine.
Meanwhile, bring the chicken stock to a boil in a medium saucepan over high heat. Add the orzo and cook for four minutes. The orzo should be only partially cooked. Use a fine mesh sieve to transfer the orzo to the large bowl with the other vegetables. Stir the orzo into the vegetable mix to combine. Transfer the warm chicken stock to a 3.4L baking dish.
Slice the tops off the peppers and remove all ribs and seeds. Cut a very thin slice from the base to help the peppers stand up.
Place the peppers in the baking dish with the warm chicken stock. Spoon the orzo mixture into the peppers. Cover the dish with foil and bake for 45 minutes. Remove the foil, sprinkle the top of each pepper with cheese and continue baking until the cheese is golden, about 15 minutes. Remove from the oven, carefully transfer the orzo stuffed pepper to a serving plate.