Preheat the oven to 180C/350F/Gas 4.
Place the pepper half into a roasting tin along with the garlic and rosemary and drizzle over two tablespoons of the olive oil. Place into the oven and roast for 10-12 minutes, until softened.
Meanwhile, heat the remaining oil in a pan and gently fry the onion until translucent. Add the chorizo and fry for a further 3-4 minutes. Stir in the cooked rice and heat through.
Remove the pepper from the oven and pile the chorizo rice inside. Place onto a serving plate and serve.
