Heat the oil and butter in a large oven proof saucepan (see note)
Fry the vegan chicken pieces for a few minutes until just turning golden. Lift the pieces out of the pan into a bowl - don't wash the pan up!
To the pan add the prepared veggies - onion, carrot, celery and potato - and cook for 5 minutes, stirring frequently
If there's any crusty bits on the bottom of the pan, add a splash of water and scrape them up - they're the tastiest bits!
Stir in the herbs, bouillon and crushed garlic
Stir in the flour until it's well distributed in the pan then add the milk, peas and reserved chicken. Give everything a good stir, flatten and level the surface then turn off the heat
Preheat your oven to 180 Fan / 200 C / 400 F / Gas 6
Uncurl the sheet of puff pastry and divide in half. Put one half back in the fridge (or freezer) for another time then cut the remaining half into even pieces - the shape is up to you!
Lay the pastry pieces over the pie filling - don't overlap too thickly
For the glaze mix the milk and turmeric together then brush all over the pastry
Bake the pie for 30-40 minutes until bubbling, golden, puffed and crisp
Notes
If you don't have an ovenproof saucepan, cook in any large enough saucepan then transfer the filling to a baking dish before adding the puff pastry lid
Recipe by The Cook & Him at https://thecookandhim.com/recipes/vegan-chicken-pot-pie/