Rusks

Here in Thailand one finds this in most bakeries/supermarkets (as 'crispy bread' etc). Problem is that it always contains some sugar no matter what the flavour is supposed to be. I'd like to make this at home - without any sugar in/on it, perhaps with a hint of garlic. This must be fairly simple to do, even in my very very basic oven - which has no temperature control.

Would be grateful for a recipe/pointer.

(Have had one go - put some garlic on a slice, chucked it in the oven and it came out thoroughly bitter and burnt.)