There are a number of restaurants that make dairy-free macaroni and cheese. Unfortunately, I have yet to find one that gets it right. Here are my takes on some of them:
1) Soul Vegetarian - It's hard to say anything too specific because the preparation is highly variable. Sometimes the macaroni are swimming in oil, other times they taste too much like nutritional yeast. Occasionally Soul Veg bakes the macaroni with herbs mixed in, which hides the nutritional yeast flavor and makes the dish taste more like a casserole.
2) Karyn's Cooked - Overpriced is probably the best adjective in this case. A tiny bowl of bland-tasting macaroni and cheese will cost you $4 (it's about $1 per forkful). The color is fairly off-putting - rather than the traditional yellow or orange, the macaroni and cheese at Karyn's is beige.
3) Chicago Diner - Of all of the restaurant versions of macaroni and cheese that I've tried, the Chicago Diner's LOOKS the most appetizing. The macaroni and cheese is covered in breadcrumbs and sprinkled with paprika, then baked. The outside edges are slightly crispy and the inside is warm and gooey. The dish would be great if only the flavor matched the appearance. Instead, it tastes like noodles dipped in soy sour cream.
4) New Ethic Cafe - If you order the vegan macaroni and cheese at New Ethic Cafe, you'll get a generous helping of orange, buttery-tasting noodles. The problem is that the butter flavor is the only flavor in the dish. I wouldn't have known that it was supposed to be macaroni and cheese if it hadn't been for the color and the name listed on the menu.
VERDICT: Don't order vegan macaroni and cheese at any of these restaurants. Particularly if you still remember what good macaroni and cheese tastes like. You will almost definitely be disappointed.