Line a large baking tray with parchment paper and set it aside.
Slice your cheddar cheese into 1/4 inch cubes. Place them on the lined sheet and cover with a dishtowel. Let the cheese dry out for at least 24 hours.
Preheat the oven to 200C/400F. Line a new tray with parchment paper. Transfer the dried cheese onto it and bake for 5-7 minutes, until popped and puffed up.
Remove from the oven and let cool completely. Use a paper towel to soak up any excess oil.
* You can use another type of block cheese but it will be much more flavorful. Do not use mozzarella. ** See the body of the post for flavor options. TO STORE: The popcorn can be stored at room temperature, in a sealed container, for up to 4 weeks. TO FREEZE: Place the popcorn in a ziplock bag and store it in the freezer for up to 6 months.