If you can't find fresh strawberries in your local supermarket, frozen strawberries may be used in this recipes; substitute two (10-ounce) cans frozen strawberries for the 2 cups fresh strawberries.
2 cups fresh strawberries, stems removed
1/4 cup granulated sugar
1 tbsp. kirsch (clear cherry brandy) or framboise (raspberry liqueur)
6 oz. white chocolate, finely chopped
1/4 cup milk, warmed
1 cup heavy cream
2 egg whites, at room temperature
Pinch of cream of tartar
3/4 tsp. vanilla extract
In a food processor, combine 1 1/2 cups of strawberries with the sugar. Puree until smooth. Strain through a fine-mesh sieve into a bowl. Add the kirsch and stir to mix. Cut the remaining 1/2 cup strawberries lengthwise into thin slices and stir into the puree. Set aside.
Place the chocolate in a heatproof bowl set over a pan of gently simmering water; do not allow the bowl to touch the water. Heat the chocolate, stirring occasionally, until it is melted and smooth. Gradually add the warm milk to the chocolate, stirring constantly until smooth. Remove the bowl from the pan of water and let the mixture cool until it is almost at room temperature.
Beat the cream just until soft peaks form. In another bowl beat together the egg whites and cream of tartar on high speed until stiff peaks form. Using a rubber spatula, fold half of the whites into the chocolate mixture to lighten it. Fold the remaining whites, whipped cream and vanilla into the chocolate mixture just until combined and no white drifts remain. Do not overmix. (At this point, you may cover and refrigerate the mousse for up to 1 day).
To serve, spoon about half of the mousse into 6 parfait glasses, half filling each glass. Top with the strawberry sauce, again using about half and dividing it equally. Repeat with the remaining mousse and strawberry sauce.