"Patissciel" (聖菓使(パティシエル) Patishieru) is an archetype consisting currently of the single Pendulum Fusion Monster "Patissciel Couverture". It shares support with the "Nouvelles" archetype, which is also cuisine-themed.
"Patissciel" is potentially a wordplay of the French words pâtissier(ière) (pastry chef) and ciel (sky). It could also be an homage to arc-en-ciel (rainbow) referencing the nature of itself as a Pendulum card.
See Nouvelles § Playing Style