This tart is filled with a bavarois mix, which is really just a mousse without the egg whites. The soft meringue is an Italian meringue where a hot sugar syrup is whisked into the egg whites and effectively cooks the whites during the mixing stage. You will need a sugar thermometer to measure the temperature of the sugar syrup. After mixing, no further cooking is required, however the meringues are usually browned quickly with a blowtorch before serving.