In a large and deep pan heat the olive oil and sauté the onion or shallot for 5-7 minutes over low heat until translucent. Add the Arborio rice and stir fry for 1 minute until the rice is fully coated in oil, add the of dry white wine and let it bubble away for 2-3 minutes until it’s reduced in volume.
Then add ¼ of the stock, 1 grated tomato and stir. Let it simmer for a few minutes over medium heat. The stock should be just above the rice when you first add it. Once you see the stock going down, add a bit more and stir. Repeat until all stock is gone and the rice is cooked but still slightly chewy. Just before you add the last ladle of the stock, add the raw prawns and green peas (could be frozen) and let them cook with the rice for about 5-7 minutes. Give everything a quick stir every time you add more stock.
Once the rice is cooked and the risotto is nice and creamy, stir in grated Parmesan cheese. Keep stirring until melted, then taste it and season with salt. Finally add in a tablespoon of butter, cover with a lid and let it stand for 5 minutes. Serve with more grated Parmesan and black pepper.