I think a common setup is this one:
2 Lights on the side, some nice background and the food in the middle. You dont have to take umbrellas in fact there is on video from digitalrev showing u how to get a nice "morning mood" effect with really simple acessoires.
Check 7:40 for the effect i described. Nevertheless fun to watch the whole video
They also have another "how to do product photography" video.
Id go with your 100mm L macro lens but try to not only take "macro style" photos with it.
Id also fake it and prepare the food myself or with help perhaps throw in food coloring to enhance things. For example for ketchup i wouldnt take ketchup only but mix red food coloring with some ketchup to make the color pop more.
Its definitly a very hard task. Ive taken food photos on ocassion on holidays or such for example and they hardly represented "the food i had and wanted to caputre on camera" anytime i looked at the photos again.
And even less it made people think "wow i wanna try that food" *chuckle*
Getting the right color for the food photographed is already very hard imho since our brains have a really detailed food memory. Im quite sure its like that so we can detect unhealthy food easily and dont get sick.
Nevertheless just try your best. Customers usually arent pickey about the food photos in my experience.
Just dont forget to write somwhere in the menu the photo is just an example and the real food may look different
. Some people are just assholes and try to make trouble if the food they get doesnt look exactly like in the menu lol. Yes iv experienced that more than once before sadly.