In a saucepan, warm the oil with the onion, mushrooms, coriander, thyme, bay leaf over medium heat.
Season well and sauté for 2 minutes.
Add the white wine, vermouth, tomato puree and caster sugar.
Stir and bring to the boil and simmer for 2-3 minutes until the liquid reduced by half. Remove from the heat and set aside to cool for 5-10 minutes.
Once cooled, serve the mushrooms over the salad leaves.