Step 1

To make the dressing, cut each tomato in half and squeeze out the seeds. Finely chop the flesh and place in a large bowl. Add the rest of the ingredients, except for the herbs, and mix well. Season well with salt and pepper to taste. Cover with cling film and chill for at least 20 mins or until ready to serve.

Step 2

Heat the oven to 200°C/Gas 6 and preheat a roasting pan. Trim any fat or sinew from the fillet of beef and season all over with salt and pepper. Heat a non-stick frying pan with a little olive oil. When it is very hot, add the beef and sear for 1½-2 mins on each side until evenly browned all over.

Step 3

Lightly oil the hot roasting pan. Transfer the beef to the roasting pan and place it in the oven. Roast for 25 mins for medium rare beef – it should feel a little springy when lightly pressed. Transfer the fillet to a warm platter and leave to rest for 10 mins.

Step 4

Serve the beef warm or at room temperature. Slice it thickly and overlap the slices on a serving platter. Pile the rocket into the centre. Stir the chopped herbs into the tomato tarragon dressing and spoon over the beef. Accompany with new potatoes if you like.