I usually like to support Persian restaurant in any city I go or visit. Flame is a descent restaurant. The concept of this restaurant is more like a fast-food joint than a lunch/dinner place. For some reasons, I have a hard time assimilating fast food to Persian food. There food is fresh and the bread is homemade.
Atmosphere 3/5: They built this restaurant in a way we feel like in a fast food joint. I like the windows to the kitchen so you can see the preparation of your order. The meat are prepared in advanced and left in a fridge. The atmosphere isn't bad, it's just not my favorite place to eat Persian food at the premise.
Food 3/5: Food is fresh and good. I wouldn't give them the price of Best restaurant in town though. It's a great concept if you're looking to eat something cheap and fast. They have a quick turn around and the meat is halal.
Service 3/5: I give them 3/5 because they are nice people. The restaurant is sort of self service so it is difficult to judge the service on that end.
Overall, a good place to eat cheap Persian food. A Sikh of Koubideh is for example $6.99 and two Sikh is $9.99. So not my favorite restaurant in Vegas but I will support them sometimes.