Make lots of soups and freeze or pressure can. You'll want to have copious amounts of bone broth to help healing. You'll also want to really ramp up the fermented foods. I would take a very strong probiotic, like VSL#3 or Custom Probiotics, while on antibiotics and for a few weeks after.
Other ideas are lots of roasts with veggies. Throw a hunk of meat in a slow cooker along with some whole veggies and some seasonings. Bagged salad is easy too.