Late in the show, Robin revealed that not only is she Vegan again, she's one-upping Veganism by going raw and denouncing sugar, grains, soy and beans. Robin went so far as to call eating grains – like rice and corn – "torture." *
She basically eats dry, plain salads.
What does she do in restaurants? "I look at the people."
Howard offered to make Robin a pizza – Since she doesn't eat cheese, it'll be cheese-less, and she doesn't eat bread, so there'll be no crust.
It'll be tomato sauce in a pan. At least she's easy to cook for.
*Ironically, Jason Kaplan is tortured by the thought of eating rice and corn as well. He'd much rather be eating Rice Krispies Treats and Candy Corn.