Cut the top 1/5 off the garlic bulb to expose the cloves. Place onto a sheet of foil, drizzle the garlic with olive oil and a pinch of salt. Roast at 170°C in the air fryer or oven for around 45 minutes until soft and golden. Once cooked, squeeze out the cloves and mash with a fork. Add the mayo and mix well. You can skip this step and use a roasted garlic paste or store bought aioli, if you wish.