Line a box mould (25 cm long; approx. 1.5 litres capacity) with foil. Soak 2 sheets of gelatine in cold water. Heat milk and 2 tablespoons of sugar. Chop 300 g chocolate and add to the hot milk. Turn off the stove and let the chocolate melt in the hot milk. Squeeze the gelatine well and dissolve in the chocolate milk. If necessary, heat up again briefly while stirring. Pour into a bowl and allow to cool
Whip 500 g cream until stiff, at the end add cocoa. Fold several portions of cream into the chocolate mixture. Fill the mousse into the prepared box form and smooth it down. Chill for at least 4 hours. Turn the mousse out of the mould onto a plate, remove the foil. Cut out a wedge along the entire length of the mousse, except for about 1 cm at each end (use this mousse for other purposes). Refrigerate again
For the orange cream, soak 2 sheets of gelatine. Mix crème fraîche with 2 tablespoons of sugar, orange zest and juice. Colour in a strong orange with red and yellow food colouring. Squeeze the gelatine, dissolve carefully. Stir 2 tbsp. cream into the gelatine, then stir everything into the remaining cream. Chill for about 10 minutes until the cream begins to gel. Whip 100 g cream until stiff and fold in. Fill orange mousse into a piping bag, cut off a small corner. Pour cream into the wedge. Carefully push the plate onto the worktop several times so that the mousse spreads well in the wedge. If necessary, refill the cream again, smooth it down. Use any leftovers for other purposes. Refrigerate the terrine for approx. 2 hours
Coarsely chop 100 g chocolate and cake glaze. Melt together over a warm water bath, let cool down a little. Carefully cover the mousse with the chocolate. Chill until the icing has solidified. Knead marzipan with icing sugar and green food colouring. Form about 8 cones, cut in the tip about 3 times with scissors. Straighten the lower end. Decorate the mousse with it. Carefully slice the terrine with a warmed knife
waiting time approx. 8 1/2 hours