Based on: https://feastgloriousfeast.com/air-fry-bacon-rolypoly/
200g Onion, finely chopped
1tsp Vegetable Oil
1tbsp Butter
6tbsp Water
90g Suet - beef or vegetarian
200g Self Raising Flour
1 tsp Salt
150ml Milk
Plain Flour, for dusting
400g Thick Cut Back Bacon
Fry off the onions in the oil and butter, adding the water near the end.
Mix suet, flour and salt together and gradually add the milk until you get a good dough. Cover and let it sit in the fridge for 5 minutes.
Roll out the pastry into a rectangle with the shortest side able to fit in your air fryer.
Lay out the bacon to cover the pastry and sprinkle over the onions.
Season with fresh pepper.
Roll up the pastry and pinch the ends to hold the filling in.
Loosely wrap in baking paper and then foil.
Air fry for 60 minutes at 160c. (In my Ninja Foodi it needed much longer, I might try Baking setting rather than the Air Fry setting next time)
Note: Try adding grated cheese or maybe some mustard powder to the pastry mix.