Thinly slice the spring onions, mince the garlic, and finely chop the red pepper.
Heat the olive oil in a large pan over medium heat. Add the spring onions and red pepper, and cook for about 5 minutes until softened.
Stir in the garlic, cumin seeds, chilli flakes (if using) and oregano. Cook for 1 minute until fragrant.
Pour in a small glass of water and the stock powder, then bring to a gentle boil. Add the chopped cavolo nero, cover with a lid, and cook for 5 minutes until tender.
Add the cooked brown rice and mix until everything is heated evenly. Season with salt and pepper to taste.
Remove from the heat and fold in the chopped parsley and artichoke pieces. If using, sprinkle with crumbled feta for a creamy finish.
Serve warm or at room temperature.