In a stockpot or very large saucepan, sauté the onion or leek and garlic in the oil over medium heat for about 2 minutes. Add the grains, rice, oregano, bay leaf, tomatoes, stock and water and bring to the boil. Drop to a simmer with the lid half on and continue to cook for about 20 minutes or until the grains are half-cooked.
Add the veggies and cook until they are soft, about 15 minutes. Add the fresh oregano and lemon zest (if using) and serve in a bowl. Garnish with spring onions.