Heat the oven to 200°C (Gas Mark 6 / 400°F).
Cut straight across the top of each pepper, and remove the seeds. Cut a jack o’lantern face on each pepper using a small knife (don’t make the holes too large or your filling will fall out!).
Set the tops of the peppers aside, and place the main bodies of the peppers cut-side-down in a baking dish. Drizzle lightly with oil, and roast for around 20 minutes, until slightly soft.
Meanwhile, add the chopped spring onions, black beans, pumpkin puree, diced feta, cooked rice and smoked paprika to a large bowl, and mix to combine. Season to taste.
When the peppers are slightly soft, turn them over, and stuff with the pumpkin mixture. Replace the tops of the peppers, and return to the oven for a further 20 minutes or so, until the peppers are soft and just starting to turn golden.