Sirloin Steak with Tarragon Dressing

Preheat oven to 160°C/GM3. Cut tomatoes in half, slice onions into 1cm rings and peel and crush garlic with the back of a knife then combine with oil, vinegar and tarragon sprigs in a baking tray and season. Roast for 25 minutes until tomatoes, onion and garlic are tender. Cool briefly, then drain oil and vinegar into a jug. Place roast garlic in a bowl and mash with a folk. Whisk in two-thirds of the oil and vinegar mixture with chopped tarragon and mustard and season. Heat a barbecue or grill pan to high heat. Brush steak all over with remaining oil and vinegar mixture, season and cook, turning once, for 5-6 minutes for medium rare or until cooked to your liking. Rest for 4 minutes loosely covered with foil, then thickly slice. Lightly brush bread on both sides with oil and vinegar mixture and grill each side until lightly charred. Top with rocket leaves, slices of steak, tomato and onion and spoon a little dressing over. Serve with remaining dressing on the side.