Preheat the oven to 180°C fan-forced.
Slice the tops from the sweet peppers and carefully remove the seeds, leaving the peppers whole. Arrange them upright in an oval baking dish.
Heat the olive oil in a large frying pan over medium heat. Add the diced chorizo and cook for 4–5 minutes until lightly browned and it has released its smoky oils.
Add the onion and cook for another 4–5 minutes until softened. Stir in the garlic, smoked paprika and saffron and cook for 30 seconds until fragrant.
Add the Spanish rice and stir well so every grain is coated in the chorizo oil.
Pour in the white wine and cook for 1–2 minutes until mostly evaporated.
Add 350ml of the chicken stock and bring to a gentle simmer. Cook for 12–15 minutes, stirring occasionally, until the rice is almost cooked but still has a little bite. It will finish cooking in the oven.
Stir through the frozen peas, taste and season with salt and freshly ground black pepper.
Spoon the rice mixture into the peppers, filling them generously without packing it down too firmly.
Pour the remaining 100ml chicken stock into the base of the baking dish. Cover loosely with foil and bake for 30 minutes.
Remove the foil and continue baking for a further 15–20 minutes, or until the peppers are tender but still holding their shape and the tops of the rice are lightly golden.
Scatter generously with extra parsley and serve immediately with plenty of fresh lemon wedges for squeezing over.