When I was a vegetarian I had no problems as a vegan I have to think about it a bit more.
My advice would be.
Breakfast – Muesli(I go with the ones with the most nuts) with banana you can mix it into porridge if you need extra carbs.
Lunch – Standard issue sandwiches, soup and bread, couscous, rice, pasta salads.
Dinner – Pasta dishes, rice dishes, couscous dishes, noodles, stir fry, green curry.
Wheat isn’t a complete protein neither is regular rice but soya and hemp are so eating those is good. Pulses and beans are excellent source of protein and minerals. I think it is important to try and eat 7 portions of fruit or veg a day. Some of the meat substitutes are ok taste wise but some are quite high in fats, others that have high protein often also have high wheat content so if you eat them with pasta dish you are really eating wheat with more wheat….