Fast casual food is fun, easy, and done correctly - a great money maker with potential for multiple locations. Burgers and fries have dominated the fast casual scene, along with pizza, for decades, but there's no reason not to branch outside of these well known concepts when looking for your inspiration. Give your customers something new to taste, and talk about - with something a little different than your average burger/fries/milkshake menu.
Falafel - a beloved staple of the Middle East, falafel is simple street food, consisting of fried chickpeas and sauce wrapped in pita. Simple to execute and delicious, falafel is growing in popularity and would make a great anchor for a fast casual restaurant. Add vine stuffed grape leaves, hummus platters, and gyro to your menu to round it out.
Ramen - we've talked about ramen before, and we will talk about ramen again. This hot new concept - literally - is sweeping the US, and with good reason. Ramen is almost universally liked, simple to execute, and cost effective. Different toppings to your bowls brings your concept to life. Create a fun, quirky brand identity which honors the Japanese roots of this concept, and watch your sales skyrocket.
Poke bowls - ramen's new, cool, Western cousin, the poke bowl is Hawaii's answer to sushi, and has the advantage of being very health conscious as well as colorful and attractive. As you're dealing with raw fish, make sure you have the kitchen skills, knives, and prep space to execute this dish safely and accurately, and also advertise that they are gluten free and low fat, yet flavorful - a rare find in fast food.
Donuts and chicken - this idea won't stand up to the health food test, but it certainly is tasty. A twist on chickens and waffles, donuts and fried chicken is a simple, cartable, and fun restaurant menu idea. This sort of concept may work better in a big city where people want and look for more variety in their offerings, but as both donuts and fried chicken and liked by, again, just about everybody, chances are you'll hit a home run with this fun combo.
