Wash the mushrooms; spin dry in a salad spinner, quarter them and set aside.
Put the duck fat, the garlic powder, and the herbes de provence in the pan of your paddle-type air fryer such as an Actifry™. Heat for 2 minutes. Stir with a wooden spoon if it clumped. Add the mushrooms, cook for 25 minutes. Add the white vermouth, cook for another 5 minutes.
Notes
Serve piping hot with grilled meats such as beef steak, lamb, etc. If you don't have herbes de provence handy, try a selection of the herbs in the mixture suggested here: www.cooksinfo.com/herbes-de-provenceTo make in a basket-type fryer: zap the duck fat for 30 seconds in microwave in a microsave-safe measuring jug. Stir in the garlic powder, herbes de provence, and vermouth. Toss the washed, quartered mushrooms in this mixture in a bowl, then cook in your basket roaster for about 15 minutes at 160 C / 320 F, toss, then cook for about another 10 minutes or to taste.