I'd do a massive pavlova (6 to 8 eggs whites, 70g sugar to each egg, whiske until totally solid then fold in some vanilla essence or rosewater, 2 tbspns cornflour and 1 tbpsn white wine vinega at the end with a metal spoon, gently). Draw a circle on baking paper around something large and round (15" plate, if you can fit that on a baking tray), then spoon in the mix. Make it higher at the sides and lower in the middle. Basically, you're making the worlds biggest meringue next :)
Bake approx 45mins at 140, then leave to cool in the oven with it cracked open.
Whisk double cream with a little bit of icing sugar (you don't want it too sweet as the meringue is sweet enough) until nearly completely solid. Spoon it into the middle of the nest. Wash and pat dry a mix of blueberries, raspberries, strawberries (although these are nicer if you can cut them a bit), and pomegranate seeds and pour the whole lots over the top of the cream.
Serve and stand back to receive massive adulation from all your colleagues.
Seriously: this looks totally stunning, everyone loves it and it really is that easy.
Good luck :)
PS You can make the meringue up to a week in advance: let it cool overnight in the oven if possible, then wrap it airtight with foil and leave somewhere cool and dry.