Beef Wellington

Doneness

Done when the puff pastry is deep-golden, puffed, and crisp all over and the beef in the centre reads 130 °F (54 °C) for medium-rare. Don't flip it — the air fryer's circulating heat browns the parcel on every side, and turning it risks splitting the seam. The pastry colour and the thermometer are your two guides: if the crust is browning too fast before the beef is up to temperature, drop the heat 10–15 °F for the last few minutes. Rest the parcel 5 minutes before slicing so the juices settle and the centre finishes with carryover heat.

Oil & seasoning

No oil spray — brush the pastry with beaten egg (egg wash) instead, which is what gives puff pastry its glossy, deep-golden bake. A second coat of egg wash just before cooking deepens the colour; oil would soften the crust rather than crisp it.

Season with: Classic: a dry mushroom duxelles (finely chopped mushrooms, shallot, thyme, cooked dry) wrapped around the seared fillet, often over a layer of prosciutto., A thin smear of English mustard or pâté on the beef before wrapping adds the traditional savoury depth., Season the fillet hard with salt and pepper and sear it before wrapping — the pastry seals in whatever crust you build., Vegetarian version: a thick mushroom-and-spinach filling in place of the beef..

Watch out for

• !Pre-sear the fillet and cool it completely before wrapping — a raw or warm centre overcooks past pink during the long pastry bake.
• !Cook the mushroom duxelles until it's dry; any moisture steams the pastry and leaves a soggy, raw base.
• !Chill the wrapped parcel firm before cooking so the pastry sets and crisps before the beef climbs past medium-rare — a warm parcel slumps and bakes greasy.
• !Make individual parcels, not one large log — a full Wellington is too big for a basket and cooks unevenly, leaving raw pastry seams or overcooked beef.
• !Use a thermometer; pastry colour alone won't tell you the beef is still rare inside, and there's no flip or visual cue for the centre.