Place the whole peppers on a baking tray and bake in the Oven for 20-25 minutes, until the skins are charred and blistered. Put to one side to cool.

Meanwhile, chop the onions into small cubes, finely chop the garlic, and de-seed and finely slice the chilli pepper.

Pour the oil into a frying pan and saute the onions and garlic over a moderate heat for 10 minutes, until soft and lightly coloured. Remove half the onions from the pan and keep to one side.

With your fingers, peel away the charred skins from the cooled peppers, then halve and de-seed them. Keeping the yellow peppers to one side, add the red peppers to the onions in the pan, along with the chilli pepper, and stir-fry for 3-4 minutes.

Pour the contents of the pan into a liquidiser with 3 tablespoons of water and blend until smooth, then season to taste with salt and pepper.

Stir-fry the yellow peppers with the rosemary, bay leaf and reserved onions in the pan for 3-4 minutes. Remove the herbs and blend until smooth in the liquidiser, then adjust the seasoning.

Cook the fettucine in salted boiling water for a few minutes, or according to the instructions on the packet, leaving the pasta cooked but slightly firm. Meanwhile, gently reheat the red and yellow pepper sauces separately.

Drain the pasta and transfer to serving plates. Pour over the sauces separately, allowing them to merge if wished, garnish with the basil leaves and serve.