1. Sweat the bell pepper in the oil for 10 mins, until soft and lightly golden. Heat oven to 350F.
2. Meanwhile, cook the rice in a medium pot of salted boiling water for 20 mins, or until tender. Drain in a fine-mesh sieve and place in a medium bowl. Lightly beat the egg and add it with two-thirds of the cheese to the rice and stir to combine.
3. Place the sauteed pepper in an 8-inch square casserole dish. Spoon the rice mixture over and smooth it out. Sprinkle over the rest of the cheese. Bake for 30 mins until bubbling and golden.