Peel and finely chop the onion and shallots and put them in a pan with the wine. Bring to the boil and continue boiling over a high heat until the wine has reduced to about 1 and a 1/2 tablespoons.

Add the tomatoes to the onions. Cover and simmer for about 10 mins over a low heat.

Rub the mixture through a sieve.(I whizz first of all in a Magimix but still sieve as the texture is finer).Put purée in a clean pan Blend the cream into the purée and bring the sauce to the boil and season.