You can get extra light mayo at 3% fat. You could try tuna pasta? I make a biiiig bowl with 60g wholewheat spaghetti, half a tin of tuna, some EL mayo and loads of peppers/cucumber/red onion/sweetcorn and black pepper. Mix it all up and it fills you right up, is low fat/calorie. It tastes amazing too. I don't do xenical so I can't tell you the fat content, but I generally aim for a lower fat, balanced diet. There can't be much fat in there.
It always does well to think about everything you can do with a grilled chicken breast too, if you haven't invested in one already, get your hands on foreman grill!! Absolute godsend, if you butterfly out a chicken breast it only takes 3-4 minutes to cook on it. You can have that on a bed of salad, on toast, or if you find a mayo you like then have chicken mayo.
Make pasta or rice with a chicken tomato sauce. Tins of tomatoes, peppers, mushrooms, onion, garlic.
Totally simple things are normally the best.
Scrambled eggs if you take out some yolk, maybe 2 whites and one yolk. Banana on toast. Fruit smoothies with low fat yoghurt + skimmed milk.
Vegetable soup.
If you can get a spray oil for frying you might want to try that, that way there isn't a huge amount of fat. Make a big stir fry, again peppers, onion, sweetcorn, beansprouts, chicken breast, some noodles if you fancy it, and there's a good sweet chilli sauce if you like more flavour. Beware the noodles are high in calories. I always find myself filling up on masses of veggies and chicken and it tastes fanastic and really fills you up. And you don't feel bloated afterwards. It helps when you're dieting to try find something healthy yo can fill up on, instead of allocating your calories to unhealthy stuff that you really like, and end up not eating enough..