Luigi's food game is on point when scouting out good restaurant recruits in the Johnston area. It takes up enough of a strip mall to give it some gravitas, but doesn't have the feel of comparable food places. You got a take-out deli with standup tables, and a restaurant that you'd be 'gagootz' to miss. (That's slang for 'crazy in the head.')
Their Amalfi Coast menu in the restaurant section has indicators of what is gluten-free and has nutritional stats on the food.
They have a surf-and-turf that beats a lot of the downtown Providence prices. Their plates will have you bringing a doggie bag home, unless you have two stomachs.
Overall, Luigi's is a wonderful experience. Check this out if your traveling down the I-295 or Route 6 corridor.