Whisk the cream into chantilly* with th sugar, then add the softened butter and mix together carefully.
Divide the cream into 3 bowls.
Mash the strawberries into pulp and add to one of the bowls. Ass the lemon zest to another bowl, and the orange zest to the remaining bowl. Mix each mixture well, and place in the refrigerator.
* How to make your chantilly Cream : www.elle-et-vire.com/en
Sift together the sugar and powder.
Separately, whisk the egg whites at room temperature with the salt until they form soft peaks, and progressively add the icing sugar, then the dry mixture. Mix well using a spatula to ensure this mixture remain airy.
To colour your shells, divide the mixture between 3 bowls, and add a drop of red food colouring for the strawberry ones, a drop of yellow for the lemon ones, and a drop of each for the orange ones.
Preheat the oven to 150°C.
Place a large sheet of greaseproff paper on a baking tray. Weigh down the corners to ensure the paper does not lift during the baking process.
Using a pastry bags with a small nozzle, make small domes of 3-4cm in diameter, taking care to space the shells out well. Set aside to rest for 15 min.
Place in the oven for 12 minutes, taking care not to open the oven door.
Remove from the oven and leave cool for 15 min before removing them delicately from the paper.
Use a pastry with a nozzle or a spoon to generously garnish your shells with the flavoured fillings.