If you really want to go as close to syn free as possible, then Welshcake's suggestion is the best one. But that might leave you feeling deprived if everyone else is having a yummy curry & you've just got meat and salad.
If you are prepared to spend a few of your day's syns, then quite a lot of the tomato/onion/lentil based curries are pretty low in syns. Just make sure you don't have a creamy one. And most places will cook it without ghee if you ask. And plain boiled rice is free, of course (assuming you're on Extra Easy, or Green).
If this is going to be your main meal of the day, then spending say half your day's syns on it wouldn't be too bad. It depends if you want wine or beer with it! If you can stick to just water that will help.
It's a question of weighing up your options. Which bit of the whole "going out for a curry" experience is your best bit?
If it's the poppadoms, then have one: but then just have chicken tikka & salad.
If it's the beer, then you might have to have chicken tikka, salad and NO poppadoms.
If it has to be the whole hog - naan bread & all - then work it out before hand. You can have a non-creamy curry, with rice, a poppadom, half a naan, and a pint, for about 32 syns. Is it worth that much to you? If so, declare a Flexi day, enjoy it, and go back to being 100% on plan the rest of the week. Or take that off your weekly syns, and split what you've got left between the days you've got left until weigh in.
There are lots of ways round it. SW is a plan for life, and has to be able to take these occasional meals out in its stride.