Start by placing the beans and mayo in a food processor.
Blend until it's as smooth as you can get it. This may take a few minutes, but it's worth it to get it nice and creamy.
Add the artichokes to the processor and process again briefly. This time, only enough to get the artichokes down into small chunks.
Now add the spinach and spices and pulse the processor, just to mix the spinach and spices into the dip. You aren't trying to actually process anything here. Just basically using the processor to stir.
Once done, just transfer it to a serving bowl or storage container.
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Notes
Please note that the nutrition data given here is a ballpark figure. Exact data is not possible.