samstar, i think your omlette meal last night was just fine, it won't take you out of ketosis. Stick to proteins and fats (more protein than fat!) and you should be ok. Green salad is also ok but don't go overboard on it because it can knock you out of keto, same with veggies. Be especially careful of some veggies, obviously potatoes, but also sweetcorn, carrots, peas - try to avoid or eat in small quantities and make up your meal with protein instead although it feels counter to what we normally do on a diet it will keep you in keto and infact lean meat is pretty low in calories. Also, tomatoes, try to avoid or just have a tiny bit.
I think some good foods for aamw (or at least what i'll be eating, lol, i have it all planned out already i can't wait!) are... chicken (take skin off to avoid fat/cals but no strictly necessary), fish of any kind, lean steak, eggs, hard cheeses (cheddar best as it has next to no carbs), herbs and spices (try to use instead of sauces, or use sauces but make sure they aren't sugar loaded), tuna (nice snack/light meal either alone or with some salad, add a little vinegar and salt yummm).