Have cheese and butter at room temperature. Whip cream and set aside. Beat egg white until stiff and set aside. In a large bowl beat egg yolk. Add Roquefort and beat until smooth.
Add cream cheese and butter and beat until smooth. Dissolve gelatin in cold water, then place dish of gelatin in hot water and stir until gelatin is dissolved.
Add gelatin and mustard to cheese mixture. Fold in egg white, then fold in whipped cream. Pour into greased mold. Chill.
Serve with crackers or fruit.