Heat oil in a large frying pan and sauté the onion until soft and golden.
Add the beef, stir well and cook until lightly browned all over.
Stir in the cumin seeds and garlic and cook for about 1–2 minutes until fragrant.
Add the tomato, quinoa, water and season with salt and pepper, bring to the boil, reduce the heat, cover and simmer for about 10 minutes or until all the water is absorbed. Stir the pan every now and then during the cooking time. Remove from the heat and stir through the parsley.
In the meantime, prepare the peppers. Preheat the oven to 400°F/200°C.
Cut the peppers in half lengthways then carefully remove all the seeds and membrane from inside. Alternatively, you can cut a slice off the top of the bell peppers from the stalk end to make a lid then carefully. Remove all the seeds and membrane from inside.
Fill the peppers with the meat filling and place into a baking dish. Cover with their lid, if you have cut the bell peppers that way, drizzle with extra virgin and season with salt and pepper.
Bake for about 20–30 minutes until the peppers are slightly charred and cooked. Decorate with chopped parsley, just before serving.