Pizza (same toppings every time)
Not a problem because I can eat Pizza Hut's stuffed crust with extra cheese forever without ever getting bored. Intestinal distress, yes; bored, no.

Second choice would be pasta for the stuffed shells or lasagna.

The only one of these that won't kill you or make you sick eventually is the vegetables and/or fruit, depending on if we follow culinary, botany, or vladdy definitions of the lines between them.

THO if we can drink whatever, smoothies and broths can probably make up for everything missing