Pre-Primal (I used to do religious fasts a few times a year) it was canned peaches. Dunno why.
Now it depends on the type of IF I'm in the midst of. 24-32 hour fasts want to be ended with a tenderloin filet seared in coconut oil (or prime rib seared in its own fat) - medium rare both cases. Nothing with it.
If, however, I'm doing some variation of the 8/16 throughout the week I usually like bitter leafy greens with maybe 2-3 oz protein and a sweet fruit (berries, orange slices, etc) with cucumbers and bell pepper to break my fast.