First, glug a generous amount of olive oil, about a few tablespoons, into a large, heavy bottomed frying pan. Then, over a low-medium heat, throw in your onions and peppers. Let them cook, slowly, for at least 30 minutes, half way through adding your garlic. You don't want to colour the vegetables, but instead make a sofrito (a slow cooked vegetable base). You want to extract the sweetness of the veggies, and soften them so they still have shape but don't have any bite left to them.
Whilst your vegetables are slowly cooking down, it's a perfect time to peel and devein the prawns. Peeling is obvious: just take off the heads, shells and tails without damaging the prawns, there's no art to it! Save all your shells and heads. To devein get a sharp knife and, starting at what once was the head end, slit a line (a couple of mm deep) right down the back to the tail end. You should be able to see a dark brown line under the skin - this is the poo pipe - follow it down with your knife. The line you've cut should enable you to remove the pipe. Put your shells and heads into a small saucepan and add about 1 litre of boiling water. Bring the pot to a boil for about 20 minutes. Drain the pink liquid over a bowl using a sieve, mashing the whole lot to get all the flavour and goodness out. It will smell very prawny - this is the essence of the dish so don't be tempted to skip it and use shop bought stock! It's not the same.
When your sofrito is ready, thrown in your fresh tomatoes and let them cook for a few minutes. These add even more colour and freshness to the whole shebang. Then add your rice and stir into the mix. Now pour in a glass of white wine and turn up the heat to burn off the alcohol. Add a teaspoon of sweet paprika and stir. Now add your stock, so that there is about a cm or 2 of liquid sitting on top of the rice. (It's OK if you have some stock left over, you can save it in case you need it at the end, although you can use boiling water if you need to.) Let the whole lot cook over a medium-high heat, just bubbling away with the lid on, for about 30 minutes, or until the rice is swollen and cooked and almost all the liquid has reduced. You'll know when it's ready. Try not to stir it, it's OK if a little crust forms on the bottom, this is desirable in fact as it's delicious.
This dish needs lots of sprucing up with fresh parsley, quite a bit of freshly squeezed lemon, salt and pepper and finally a drizzle of very good extra virgin olive oil to serve. A fresh green salad with a lemony dressing goes well alongside. I use the lettuce leaves to scoop up all the rice and prawns!