Does flash work, or only continuous light?

Continuous light, in the colour of the room, lets you see the sauce shine while the plate is set. A straight flash does not work: it flattens the cut and puts a white spot on the glass. Try without flash by the window and add light only if the plate is still in shadow. In Madrid dining rooms the ceiling flash fires on its own and the menu ends up with flat dishes. The series is made in the light the table already has, helped if needed, never with a flash aimed at the plate.