Not too long before you sit down to eat, peel the pineapple and remove the core. Slice thinly, and place in a bowl, with the pulp from the passion fruit. You can extract the pulp - the insides - by scooping it out with a teaspoon and add a dusting of icing sugar. Turn gently to mix, then leave to mascerate (much the same as marinate) until ready to eat.