Clean the rhubarb and cut into 3 cm long pieces. Clean the strawberries and cut them in half. Melt sugar (1) in saucepan until golden brown caramel. Extinguish with juice of one lemon and 6 tbsp water.
Make 5 min. in open saucepan. Add rhubarb and cook for 3 to 5 min. in closed saucepan, fold in strawberries, cool.
Butter 6 ovenproof cups or ramekins (150 ml each) and sprinkle with sugar. Beat egg yolks, sugar (2) and lemon zest until very creamy. Stir in curd cheese and cornstarch. Whip egg whites with sugar (3) until stiff and fold in carefully.
Pour the mixture into the cups or ramekins and cook in a hot water bath at 180 degrees on the lowest rack for 20 minutes.
Loosen the souffles at the edges with a kitchen knife, turn them out of the molds, dust with powdered sugar and serve with the compote.