2 pounds potatoes (Yukon gold, white, or red potatoes are best, but or baking potatoes, like russets, work well too)
Too much butter
Too much olive oil
6 cloves garlic, diced
1 medium-size cooking onion, diced
1/2 cup fresh rosemary, thyme, or dill, stems discarded before measuring
Salt and freshly ground black pepper
It's all in the timing of adding the garlic and onions (which can only really be learned through trial and error). Adding them too soon will cause them to burn before the potatoes are crisp, and too late will prevent the garlic and onion from fully caramelizing.