For the dates stuffed with Roquefort mousse, soften the gelatin in cold water. Crush the cheese in a bowl until it is very fine. Heat the port in a saucepan. Squeeze the gelatin well and add it to the warm port while stirring. Add this to the Roquefort and mix.
Whip the whipped cream until stiff and fold in the cheese. Put the mousse in a piping bag (not too small a piping nozzle) and let it stiffen in the refrigerator for about 1.5 hours. Cut the dates in half and remove the seeds. Fill the dates with the Roquefort mousse and arrange the date halves around it.