The foods that are the least likely to give autoimmune or mood flare ups on the diet include wild carnivorous fish like wild salmon, wild mackerel, tuna, and honey. Make absolutely sure the fish is wild and not farmer (even organic farmed needs to be avoided). These foods seem to be tolerated fairly easily for a first reintroduction. Make sure you give your body a few days to adapt once reintroducing and monitor for new symptoms. If that goes well, pressure cooking organic carrots and parsnips in broth and drinking the broth is a very slow and careful way of reintroducing vegetables. If that goes well, slowly ramp up the amount you’re eating each day. You can start with as little as half a teaspoon of cooked vegetables each day and increase from there.
Some foods to start with include: peeled and cooked apples, pears, carrots, parsnips, beets, turnips, coconut, duck, and chicken (pasture raised not fed corn or soy).
The GAPS diet is a good place to look to reintroduce although I don’t recommend reintroducing dairy for those with autoimmunity. And if you have histamine intolerance or an issue with aged meat then fermented food may also be an issue. Start with introducing the above foods and if that goes well then further reintroductions should be much easier.