Toast bread and put each slice on a warmed plate. Melt butter in a pan, slice tomatoes thickly and fry gently in butter for two minutes a side. Sprinkle basil over the top, season and lift tomato on to toast. Keep warm. Turn the heat up under the pan, pour in double cream, swirl round to pick up all the juices and, as soon as it bubbles, pour over the tomatoes and serve quickly