Ok way too much rice. 20 cups max, 1/2 white and 1/2 brown. Brown forms a slightly stronger gluten to help hold the roll together.
Make up the 6 remaining cups with a blend of seasoned soy crumbles or a dark bean - kidney or black, and some onion. And the seasoning - could go so many directions with the same base ingredients - savory, or hot, or even bbq...
Also long-chain margarine? Why? At Sysco [PDF] they could get a HDL-ish soy-based shortening for about the same. Why should food-as-punishment raise my tax rates for inmates having heart attacks because of unneeded heavily saturated trans fats in a freaking vegetable dish? Hell, if you're going to do that just serve rat poison.
Yeah, you know if you're going to f with a man's food, don't serve a half-assed vegetarian roll, just serve gruel as the stick. And maybe use an improved vegetarian roll as the carrot.
PA DOC "food loaf"