He's perfect for the role, and he's a vegetarian. Big deal. Craft service is an important part of taking care of your people -- especially if you're not paying them. "Meals, credit and copy" is all a lot of folks will ever get. So take good care of them, and they'll take good care of you.
This is true, and important. On a low-budget project craft service is one of the few ways in which you're able to demonstrate to your cast and crew that while you don't have a lot of resources, you'll still look after them where and as you can. And that can definitely affect their performance.
Don't underestimate the psychological importance of food. Sounds silly, but it's not.
You want silly, try the time we had to tear every last scrap of meat off a roast chicken carcass, then build it back up into a chicken-shape using tofu 'meat,' because no one bothered to determine whether or not one of our leads was a vegetarian before it was time to set up the tears-apart-a-chicken-with-his-bare-hands-and-eats-it scene.