potassium help required

Hi

Does anyone have any tips for raising potassium levels without supplements (supplements always upset my stomach).

I eat lots of potassium rich foods like avacado, spinach, chard, yogurt.

I cant tolerate fruit or nuts.

Ideally something I can have in between meals for a boost.

Also I have heard wheatgrass is good but I have a really bad reaction to wheat so dont know if this would cause me problems or not (does anyone know if this would be the case).

Thanks for reading