For the background, black or white is ok.
Just control the lighting at the back, make sure it would not shine on the area that you want it in black.
In Chinese, also say "dark is deep, light is out" (深入浅出)。
As a photographer must know to control camera and light.
Control camera is easy but lighting is not.
For reflector at the left, make sure it show the texture at left of your cooking stove .
Happy shooting!