Remove the leaves from the cauliflower and cook it with 250ml of cold water along with half the garlic puree in the Instant Pot on the steam basket on manual for 20 minutes.
Peel and dice the onion, carrot and place it in a large pan on the hob. Also dice and de-core the red pepper and the tomatoes. Add them to the pan as well. Season with salt, pepper and oregano. Give it a good stir and then allow to cook on a high heat for 10 minutes, until the tomatoes are nice and soft.
Remove the skin and dice and clean the leeks. Add them to the pot too. Give it a good stir and add to it ½ of the garlic puree. Cook for a further 5 minutes.
Remove ¾ of the mixture and place in the blender along with the can of tinned tomatoes. Blend until smooth and then re-add to the pan.
Add the mince along with the basil and a bit more salt and pepper. Cook for 10 minutes on a medium heat until the mince is well cooked and then turn off the heat and put to one side.
Remove the cauliflower from the Instant Pot and add the cauliflower and the water from the Instant Pot to the blender. Also add milk, salt, pepper, mustard and parsley and blend until it resembles a smooth sauce.
Take the cauliflower sauce to a small pan and add in 80g hard cheese along with the soft cheese. Stir until the cheese has melted and it has that delicious creamy cheese sauce texture.
Put together the lasagne. Inside the Airfryer baking pan have a layer of the mince, followed by lasagne sheets, followed by mince, followed by lasagne sheets and finished with the cheese sauce. Finish with a layer of cheese on top.
Place the baking pan in the Airfryer and cook for 25 minutes at 170c/340f.