Let's start cooking!
Preheat the oven at 160 °C. Place the Caramelized biscuits in the oven for two minutes and then cut them in two.
Slice the red onion into rings. Bring the vinegar and sugar to the boil, pour over the onion rings and let marinate for a while.
Place a cube of paté on top of the Caramelized biscuits and garnish with Sirop de Liège and a marinated onion ring.