You probably need to stay under 30 g of carbs a day. This is a very low carb ketogenic diet. Some people can go higher than that and stay in ketosis, but most people are in ketosis on that level. Once you are in ketosis for a while, your appetite will be really curbed.
Remember, you can subtract fibre from your carb count because your body can't break fibre down into sugars. In the UK it's a little harder to figure things out because the sugar listing isn't the same as in the US. I find the easiest thing to do is to use fresh/whole ingredients, and look up the carb counts on the web or in a carb count book. I may have one around here, and if I can find it, I will send it to you if you'd like.
For instance, a huge, high protein, low carb salad could give you really minimal carbs:
1 HB egg
1 cup shredded lettuce
3 slices streaky bacon or pancetta
1 oz blue cheese or Roquefort
1/2 an avocado
2 oz chicken breast (add more if you're hungry)
2 cherry tomatoes
Total carbs: 13.05 BUT taking out the fibre, which your body can't break down into sugar:
6.86
These counts were taken from the Active Lowcarber myplan tool which you can use if you register with their forums.
Notice I didn't add dressing to that. That's a personal choice. If I were making that salad, I'd make dressing with the blue cheese (instead of just adding it) and add the carb count. On many salads, I'd just add oil and salt and pepper, but I love blue cheese dressing. If the carb count is still too high (it shouldn't be), you can take out the avocados, but you really need the fat if you're not going to be eating carbs.
When I first started low carb, I'd eat a salad every day for lunch. Even when I was making something like tuna or egg salad, I stick it in a bed of low carb vegetables.
Tuna mixed with sprouts, mayo, garlic, salt, pepper and a low carb crunchy bits (seeds, nuts, and there are others) is one of my favourite low carb snacks.
Stuffed tomatoes (basil, cottage cheese if it's ok on your plan, mayo, nuts mixed with the insides of a tomato then stuffed back inside)
Grilled onions (wrap an onion in foil with some butter stuffed in, throw on BBQ with meat or in oven along side it, salt when done. It's sweetish and not oniony at all)
Homemade Kebabs
Pizza without eating the base
Burgers wrapped in lettuce
There's muffins you can make with flaxseeds, cream of tartar, and eggs, but I can eat them for the same reason I can't eat unfermented soy. Hormone positive breast cancer runs in my family, so I have to avoid phytoestrogens. People who can eat them seem to love them.
Good luck.