With the beta release of Unreal Engine 5 we got the new feature of Lumen lighting. The easiest way for me to describe it is real-time global illumination. Objects of your scene affect other objects based on their color and reflective nature. This is even more true for emissive objects.
Take this candle flame for instance. This is a fairly simple emissive material assigned to a plane with a panner attached to it. So it somewhat flickers and moves in the scene. This light is then reflected in the area in which it illuminates. This is how you set it up. First, start-up UE5 early release and import the base image file below into your content browser.
After you have the image imported, right-click on the image and convert it to a material. Inside your material create the functions as shown in the material graph below. Note that the TexCoor will need to be adjusted to your desired effect as well as the speed of the Panner. All the other items should be straightforward.
Now you have a shimmering candle in your scene that is illuminating the objects around it without adding any additional light object into the scene. The beauty of Lumen!