Preheat oven to 425.

Slice each head of cauliflower at the base into 4 large slices.  Each head will only get 2 steaks out of it that stay together and the end slices you can set aside for roasting separately!

Take your 4 cauliflower steaks and place them on a foil lined baking sheet.

In a small bowl combine olive oil and liquid smoke and whisk to combine.  Pour over the steaks and spread it around with your hands to coat them.

Then in another small bowl combine arrowroot, garlic powder, salt and pepper.  

Use a sieve to lightly disperse that mixture over the cauliflower steaks, turn them and repeat.

Place in the oven and cook for 20 minutes, flipping them halfway, or until fork tender.