1. Omelettes (scrambled eggs) - I usually use 4-5 large eggs and eat half for breakfast and half for lunch. I toss in diced veggies (red peppers and spring onions are a favourite), sometimes a small chicken or turkey breast or some lean ham. A serving is usually around 250 calories.
2. Cottage cheese with lean ham, diced red peppers or diced radishes, herbs and spices - around 250-300 calories.
3. Skyr with nuts - skyr is an Icelandic dairy product high in protein and very low in fat. Ideally use the non-flavoured version and add your own low-calorie flavouring and sweetening. Careful with the nuts, as they are high in calories (but oh so delicious).
4. Chicken or turkey sausage/pan-fried chicken or turkey breast with a slice of whole grain bread.
5. If you're in a hurry, a home-made protein bar (protein powder, peanut butter, oatmeal, cocoa powder and your sweetener of choice, all mixed together, shaped into bars and refrigerated). The recipe that I use has about 250 calories per bar.