I love making my own souvlakis - I think you call them kebabs in the UK (to us, kebab is meat on a stick). Get some low calorie flat bread - mountain bread is very good, I'm not sure if you guys have that brand? Grill some lean beef, lamb or chicken in a non-stick pan with no oil. Have it cut into strips like you would for a stir-fry. Add lots of salad like fresh, shredded lettuce and juicy chunks of tomato. I like spreading low fat Greek yoghurt onto the flat bread and adding some sweet chilli sauce but you can use any combo of low-calorie sauces you want. This is good for 300-450 calories, depending on what ingredients you use.
I also love making chunky hot chips out of sweet potato. If you look up sweet potato on calorieking.com or some calorie site like that you can get a nice serve of chips for not many calories. Cut your potatoes into chips, toss them in some salt and pepper and maybe a little bit of oil and bake them in the oven. Serve with low calorie sauces / low fat yoghurt. Om nom nom nom