You'll hear a lot of anecdotal stories about diets that "cure" autoimmune conditions. They work for some people, but not for everyone and there's no way to know what will work specifically for you.
Your doctor may suggest trying the Autoimmune Protocol diet (AIP), which is a diet specifically designed to identify foods that trigger your systems. Again, not everyone is triggered by foods, but since the immune system is linked to gut health some people do find success in this. The key thing with the AIP is that it is meant to be used as a tool to isolate and then reintroduce foods slowly into your diet to identify things that trigger your condition. Upon completion of the reintroduction phase, you can then avoid your triggers but otherwise resume a normal diet. While some people prefer to stick to a strict elimination AIP, that is not the ultimate goal of this diet.
If you prefer a more general avoidance list, many people say to just avoid inflammatory foods, which include processed meats, sugars, and refined carbs, and to eat anti-inflammatory foods such as leafy greens, nuts, fruits, and fatty fish.
Ultimately, you're going to need to experiment a bit to see what works for your body and helps avoid your flares.