Preheat oven to 180°C. Line two baking trays with baking paper.
For praline, place sugar into a heavy based saucepan with water over low heat and stir until sugar dissolves. Increase heat to high and cook without stirring until golden brown.
Remove from heat and immediately stir through nuts. Pour mixture onto a greased baking tray. Spread with a palette knife and allow to set. When praline is cold and brittle, crush into fine pieces with a rolling pin.
For the parfait, grease and line a 1.2L loaf tin with a strip of baking paper long enough to hang over the sides.
Combine banana with a teaspoon of lemon juice until it forms a rough paste. Beat egg whites with remaining lemon juice until stiff peaks form. Slowly add sugar and beat until dissolved and a shiny meringue has formed.
Gently fold in cream, banana paste and half the crushed praline. Spoon into prepared loaf tin, smooth top and freeze until firm, approximately five hours or overnight.
For the tuile, beat egg whites until fluffy, add sugar and beat until dissolved. Add melted butter and flour alternately until combined. Fold in lemon rind.
Drop teaspoons of mixture onto prepared trays and spread thinly into a strip. Bake for 5-6 minutes and remove from oven. Allow to cool and gently remove from baking paper.
For the bananas, spread sliced bananas out on a baking tray and scatter heavily with sugar. Use a blowtorch to caramelise the sugar (or sauté in a frying pan for around five minutes).
To serve, remove parfait from freezer and allow to soften slightly. Place two thin slices on a serving plate, topped with a strawberry. Dust crushed praline onto the plate and decorate with tuiles topped with caramelised banana.