How to develop a butterscotch flavor in a savory sauce There's a restaurant near my house that serves a thin sauce with their steaks that tastes almost like a spicy, savory butterscotch sauce.  The chef won't tell me anything about what's in his secret sauce.

Has anyone else had a savory dish that includes butterscotch flavors?  And does anyone know what ingredients and/or techniques can be used to develop these flavors?
Most likely, brown sugar and butter is the base. Salted butterscotch is quite nice as a dessert; you could easily add spices as it cools, and potentially dilute it with oil, cream or wine; it doesn't tend to taste very sweet when salted, anyway, if the brown sugar is sufficiently caramelized.

Alternatively, you might just be encountering a brown butter, which is butter cooked until the milk solids slightly brown. Usually this is strained with a fine mesh to separate some of the solids, but not always. Salt and pepper can be added for flavor, not to mention other possibilities. I've often made brown butter by cooking it with fresh sage until the sage crisps, then removing the herbs as the butter finishes browning.