Add the potato and cauliflower to a saucepan of cold water and set on a medium heat. Bring to the boil. Cook for 10-12 minutes until soft and cooked through. Drain well. Mash and leave to cool.
Once the mash has cooled add the cheese, garlic granules, onion powder and 20g breadcrumbs. Stir to distribute evenly. Season to taste with salt and pepper.
Preheat the air fryer to 170°C and line the basket with non-stick baking paper.
Take a little of the mixture and roll between your hands to create a 4cm-sized ball and place onto a plate. The mixture should make 16 balls.
Add the remaining breadcrumbs to a plate. Working one at a time, dip each ball into the breadcrumbs getting an even coating all over. Place the coated balls into the air fryer basket. Once all the balls have been coated, spray with low-calorie cooking spray. Cook for 15-20 minutes until golden brown.
To make the cheese sauce add the flour to a microwavable jug, along with 1 tbsp of the milk. Whisk into a smooth paste. Add in the rest of the milk and whisk again.
Heat in 1 minute blasts in the microwave, whisking in-between until the mixture has thickened (ours took 3 minutes but this depends on your microwave). Add the Dijon mustard, paprika, spreadable cheese and Cheddar cheese, then whisk until melted and smooth. Season with salt and pepper to taste.
Serve the balls with the cheese sauce and an accompaniment of your choice.