1. Using a sharp knife, cut off all the peel and white skin of 1 orange and carefully remove the supremes. Place all the orange supremes in the bottom of a dish.

2. Grate the zest of the lemon, lime, and 2 oranges. Place all the grated zest in a saucepan with the water and sugar.

3. Heat gently until the sugar is dissolved. Remove from heat. Squeeze the juice of all the remaining fruits and mix in the saucepan.

4. Filter the liquid into a measuring cup to remove the zest. Sprinkle the gelatin over the liquid and mix until dissolved.

5. Pour a little of the jelly over the orange supremes and refrigerate until set. Let the rest of the jelly cool to room temperature, but do not let it set.

6. Pour the cooled jelly into the dish and refrigerate until firm. To serve, invert the jelly onto a plate and decorate with fruit slices.