Looking for diet advice

Looking for a bit of advice on my diet folks.

I'm female, 30 and not particularly interested in losing weight. Been around 63kgs for about five years and happy enough with that. I'm 5'8".
Every week I do two mixtures of cardio and weights at the gym (around 60 minutes) and two 90 minute martial arts classes.

I'm looking for more energy and maybe some suggestions on dinners etc based on the fact that I work long days sometimes and find it hard to eat properly.
I usually work from 10-8pm in an office with a microwave. I always bring lunch with me but not dinner and that's where the problem lies!

Breakfast 8am - Porridge with soya milk/unsweeted museli with blueberries and soya

Snack 11am - Banana

Lunch 2pm - Typically a salad with leaves, avocado, mackerel, olives, tomato, maybe a slice of McCambridge's bread

Snack 5pm - Sometimes nuts, sometimes chocolate Buttons

Dinner - Hmm. When I eat at mum's it's always decent, loads of veg and meat. When I don't, it varies wildly.
If I get home at a decent hour I'll have a stir-fry, sometimes with Quorn, always with veg and brown rice. I also eat a fair bit of fresh pasta with a tomato sauce of some sort.
If I'm stuck late in the office it varies from M&S Count on Us microwave jobs to a Thai takeaway.

Any ideas on what I can take to work for dinner, or anywhere else I'm falling down on my diet?

edited to add: I avoid dairy whenever possible, do take calcium supplements though.

rubadub

I would get whatever meat is on sale at the moment. Collect sauce jars, like uncle bens etc, or get containers. Now cook up a big pot of something at the weekends, fill 5 jars for the next week, calculate the portion size if that concerns you. Then cap immediately and leave in the fridge, you might want to freeze 2-3, but the others should keep. e.g. cook sunday evening and chill and use on monday, tuesday.

A full jar of meat based "stew" will do me 2 meals. You can cook pasta or rice fresh in work in the microwave and add in half a jar of curry/spag bol/stirfry etc.

If you have lots of jar you can make lots of different ones and freeze them, then you have a better selection during the week.

Thanks for that, good idea.
It'll stop me ringing Dominos at 8pm when my stomach is falling out with the hunger!