on the front burner

:  forehead

:  the whole face

:  external and often feigned appearance especially in the face of danger or adversity

:  to have the front or principal side adjacent to something

:  to have frontage on something

:  to serve as a front

:  of, relating to, or situated at the front

:  acting as a front

:  articulated at or toward the front of the oral passage

: frontispiece

:  one that burns: such as

:  the part of a fuel-burning or heat-producing device (such as a furnace or stove) where the flame or heat is produced

:  a device for recording data on an optical disk