Step 1 Preheat oven to 220°C. Combine rhubarb, brown sugar and 2 tablespoons water in a saucepan over medium-high heat. Bring to the boil. Reduce heat to low and simmer, covered, for 5 minutes, until rhubarb is tender.

Step 2 Add strawberries and zest to saucepan. Simmer, covered, for 2 minutes. Divide mixture between 4 x 1-cup ramekins.

Step 3 Place egg whites into a bowl. Beat with electric beaters until soft peaks form. Gradually add caster sugar, beating until sugar dissolves. Carefully spoon over rhubarb mixture. Bake for 8–10 minutes, or until golden.