Been doing some research online for restaurant vouchers. Wrote a blog post about it here: listsforlifeblog.com/2016/02/23/4-great-ways-to-eat-out-for-less/
Zizzi's are doing a competition online to win a holiday to Sardinia but also this competition, it also gets you money off vouchers for their restaurants for food, cocktails and prosecco. You can also win a meal for 4 people.