Bring everything except the tomatoes to the boil in a wide pan with 120 ml water and boil for 4 minutes. While it’s cooking cut each tomato into quarters, then cut out the seeds and the membranes with a knife, reserving them. Add the petals (quarters) to the boiling syrup, gently stirring as you do so, turn the heat off and then leave them to go cold. Peel their skins off using your fingers (reserve the skin), place the petals into a container and strain over just enough syrup to cover them. Keep in the fridge for up to 4 days.