You may only be able to start with coffee, tea, hot chocolate, and pre-wrapped pastries to keep it simple depending on your coffee cart’s size and accommodations. Base your menu around what your coffee cart can successfully store in between customer visits. If you can refrigerate some cold sandwiches and prepped salads, this could increase your profit margin as long as you see that your clients are inquiring about these meal items. If you can microwave pre-made breakfast sandwiches on your coffee cart, this would increase profit as well.