Dressed tomato salad with smoked mackerel and Thai basil. Photograph: Harry Weir Photography Sat Aug 08 2026 - 04:54Serves: 2Course: LunchPrep Time: 15 minsIngredients 4 or 5 heirloom tomatoes, mixed variety3 tbsp good quality olive oil1 tbsp wholegrain mustard1 tbsp sherry vinegar1 tbsp caster sugarSea salt50g thick Greek yoghurtZest of half a lemonSea saltBlack pepper2 good quality hot-smoked mackerel filletsHandful fresh Thai basil leavesBlack pepperCut the assortment of heirloom tomatoes into wedges and place in a large bowl. Add the olive oil, wholegrain mustard, vinegar and sugar to a small bowl and season well with salt. Stir to combine, then pour the marinade over the tomatoes, stirring them gently to coat evenly. Cover the tomatoes and leave them to marinate for two hours at room temperature.Add the thick Greek yoghurt to a bowl and season with lemon zest, salt and black pepper.To assemble, spoon some seasoned yoghurt on to serving plates and spread out with the back of a spoon. Arrange the marinated tomatoes on top of the yoghurt. Tear the smoked mackerel into small pieces and place on top of the tomatoes. Spoon over some of the leftover marinade from the bowl. Garnish with some Thai basil leaves and finish with more cracked black pepper.Mark MoriartyMark Moriarty is an award winning chef, TV host, author and Irish Times columnist.