Rhubarb-Strawberry-Lemon Verbena Swiss Roll with Elderflower Quark Mousse

Cook rhubarb with 80g sugar and lemon juice in a pan over medium heat for 5 minutes. Add strawberries and chopped lemon verbena, cook for another 3 minutes. The compote should retain some texture. Cool completely.

Soak gelatin sheets in cold water for 5 minutes. Squeeze out excess water and dissolve in a small pot with 3 tbsp water over low heat. Cool slightly.

Preheat oven to 200°C (180°C fan/400°F). Separate eggs. Beat egg yolks with 100g sugar until pale. Whip egg whites with remaining sugar to stiff peaks. Mix flour, cornstarch, baking powder, and salt. Fold yolk mixture into whites, then gently fold in flour mixture.

Line a baking sheet with parchment paper. Spread batter evenly (about 1cm thick). Bake 10-12 minutes until golden. Dust a clean kitchen towel with powdered sugar, turn hot sponge onto it, remove parchment, and roll immediately. Cool completely.

Mix quark with powdered sugar and elderflower cordial until smooth. Stir in dissolved gelatin. Whip cream to stiff peaks and gently fold into quark mixture. The mousse should be light and creamy.

Carefully unroll the cooled sponge. Spread half the elderflower mousse evenly, leaving a 2cm border. Distribute the cooled compote over the mousse. Add remaining mousse and roll up again.

Wrap the filled roll in plastic wrap and refrigerate for at least 2 hours to set. Before serving, dust with powdered sugar and cut into 12 even slices. Garnish with fresh strawberries and elderflowers if available.