To make the saffron mayonnaise, heat a small non-stick frying pan over medium heat until hot. Remove from the heat, add saffron threads. Shake in the hot pan for 30 seconds then tip threads into a small bowl. Add the water, set aside for 5 minutes to infuse. Whisk the mayonnaise and horseradish together. Stir in the saffron and water, season. Cover and set aside until ready to serve.
Separate the leaves from the baby cos, wash and pat dry with paper towel. Slice the tomatoes into quarters lengthways and place into a bowl. Slice 4 Qukes® into rounds and add to the tomatoes with the prawns. Combine the oil and chilli flakes, spoon over the tomato mixture, season and stir gently to combine.
Arrange lettuce leaves on serving platter. Dollop a spoonful of saffron mayonnaise into the centre of each. Top with tomato and prawn mixture. Season and garnish with micro herbs if desired.