The other day, I had one of the best hamburgers I've ever had in a lifetime of eating burgers at places in Los Angeles.
The Whole Foods Market. The one at Third and Fairfax.
They have a counter that prepares hot foods. The burger was good, organic beef over some sort of charcoal-type grill. They have all the usual toppings.
The Whole Foods Markets also have a hot food bar, a salad bar and a soup bar. I picked out some side dishes from there. If you want something unusual on your burger, you could probably find it there and add it.
I don't know if the same thing is available at all the other Whole Food Markets but I'll bet it's available at some. (In a month or so, they start building a new one near Hollywood Blvd. and Western.)
I sometimes find Whole Food Markets very disappointing. Things look good but they're overpriced and low on taste. But this burger was excellent.