1. Roasted rat on a stick: Sometimes, you just can't beat the classics.
2. Pork Chop/Roast Pork/Ham: We've got pigs and boars. So why do we not have a meal based on a nice, juicy slab of cooked pork?
3. Sausage: Similar to the above suggestion.
4. Moss: Some kind of genetically modified moss grown for human consumption. Really fits the whole underground thing and probably the closest most people get to eating actual vegetables.
5: Old world fruits and veggies: Did some research and a surprising amount of fruits and veggies can be grown in hydroponics. Some do better than others. Tomatoes, grapes, bananas, peppers, onions, radishes, spinach and strawberries are just some of them. A luxury that mostly upper class types get to enjoy.
6. MRE (Meal Ready to Eat): Military ration pack. Not very tasty but dehydrated and vacuum packed for long shelf life and chock-full of nutrition. Just add water and dinner is served. Comes with a plastic fork, a sugary energy drink (some mixing required) and dessert (usually a chocolate bar).
7. Biocorp/Protectorate issued ration: A cheap ration made to feed the hungry masses. First introduced by Old Biocorp shortly before they collapsed and recently re-introduced by the Protectorate. No-one quite knows what the hell it's made of and theories abound; Some think that it's made of ground up roaches, certain particularly schitzo types think that it might actually be rocks somehow transmuted into edible form. And some others speculate that it might be proccessed human flesh. There's also a quest tied to this one where you learn the truth.
Lastly, I have a question: We have the bacon and cheese sandwich right? So where exactly does the cheese come from? Is it actually cheese?