Drain gungo peas and put into a large pan with 500ml water, onion, carrot, celery, garlic, oregano, pepper and ginger. Bring to boil and keep at a rolling boil for 10 minutes. Reduce heat, cover and simmer for 40 minutes.
In a small saucepan, melt butter and gently fry chilli for 1 to 2 minutes. Add rice to saucepan and stir to coat in butter. Add paprika, coriander, turmeric, cumin and tomato Puree. Stir to gently cook spices, taking care not to burn.
Add Rice and spices to the cooked gungo peas.
Add more water as necessary and salt to taste. Simmer rice and peas for around 30 minutes or a little more. Check every 5 minutes and add a little more water as necessary (give a good stir to make sure it is not sticking to bottom of the pan) until rice is cooked through and tender.
These measurements will give a generous serving for 2 people, or if accompanied by pitta bread or garlic bread would probably serve 3.