1 hour ago, aperture said:Sounds like clarifying the butter on the stove and then "steeping" the clarified butter with onion/garlic/spices in a 275F oven for a couple of hours would be safe (I'm confident that my oven can maintain 275).
If you had read the thread I linked to, you would have seen posts by MaxH outlining how difficult it is to get oil at or above temperature under regular atmospheric pressure. This is why acidulation then pressure frying are recommended.
There is only one scientifically proven method for home cooks to make a safe garlic oil. HERE is a link to a page run by Clemson University's extension service. (a place where real science happens, not a suzie-hommemaker clickbait website)