I'm unlikely to have to worry about this, but I do NOT get this 'service charge' business.
Why not just add whatever % it is into your price, and then just LIST THAT. I know all about the psychology of advertising $9.99 (+ $3.00 service charge in small print) gets you more business than advertising $11.99 all inclusive, but does that translate once someone is in the restaurant? Especially one that isn't explicitly appealing to commodity-rules pricing structure. (presumably, one is eating at Gjelina for an experience that is not equivalent to maximizing one's calorie per dollar ratio.)
"Here at Gjelina, we believe in a fair, livable wage for all our staff. Our prices reflect the cost of our ingredients and the time and labor required to prepare them. We have a strict no tipping policy, and 15% of each pre-tax bill is split by all our staff. Thank you and bon appetit."
There. I just saved some poor office drone the trouble of opening his calculator app on his phone.