Healthy Cooking for One!

I also cook for one. I like to make things in batches. Might take a bit longer the first time but then it's ready to eat or just heat through the other times!
Some staples:
--Hummus (put everything in a blender and whizz until smooth: 400g tin of chickpeas, drained and rinsed, 1tbsp tahini(sesame paste - should be near greek/middle eastern stuff), 1 or 2 cloves garlic, then add flavourings to taste such as lemon juice(traditional, plain hummus), roasted red pepper(I get these in a jar), pesto, or whatever else you fancy. Serve with crudites, pitta, falafel or as a dip or sandwich spread)
--Ratatouille (chop up a load of veg into 2cm-ish chunks - whatever you have to hand really but more traditional is onion, garlic, aubergine/eggplant, courgette/zucchini, bell peppers. Sweat down onions with some oil, then add garlic for a min or two, then add veg to the pan - longest cooking time first until all are cooked/browned/softened a little then add a tin of chopped tomatoes and herbs of choice and simmer until moist but not soupy - you can add some water/stock if it's too dry or the tomatoes don't cover enough. Keep it in the fridge and heat some up as a side, cold with salad or warm with pasta/potatoes/bread or add some lentils/potatoes/egg/meat to bulk it up)
--I'm sure you can find lots of good batch recipes with a little googling - moussaka/cottage pie/curries etc. A lot of them can be frozen in portions so you don't have to have the same thing 5 nights in a row! I'm veggie and since you mention meat all my lentil concoctions might not be to your taste (they are cheap though!)

Quick and easy classics from my student days were rice/pasta(could be brown/wholegrain) with veg and store bought sauce (adjust the ratio of pasta to veg to fit your calorie allowances and watch out for sauce calories! Obviously you can add meat if you like but I can't advise what type!), soup - homemade or store bought with bread or croutons, baked potato (Ok it takes a while to cook but you can just oil it, fork it and shove it in the oven and come back later! And then you can put whatever you fancy on it!), veggie(but you could use meat) burger with salad with or without bun.

Not overly adventurous but I hope some of that helped?! Bon appetit!

A really inexpensive fried rice is with veggies (I used onions, carrots, and A LOT of spinach), scrambled eggs, and ketchup. It reheats well too.
I also enjoy baking tofu cubes/sticks ahead of time to snack on later on, or put on a bed of greens/ rice with sauce.

A meal I have recently made loads and love is cous cous with veggies in a tomato-based sauce. Any veggies will do but I usually use broccoli, courgette, carrots, mushroom and fresh chillies (onion and garlic too for more flavour) in chopped tomatoes or a readymade pasta sauce with salt/pepper/oregano and lots of lime when you serve. For protein, I usually add two sausages, which I love, but pretty much any meat would go! It comes to about 5/600 calories for a serving and really satisfying

Also - any soup that freezes well. I make a big batch, store in mason jars and freeze. Good grab and go for days you're not prepared. Just make sure you leave space for expansion when it freezes. Depending where you live, it may not be soup weather anymore, but I'm in WI and it's in the 40's.

my fave site for recipes is Skinnytaste.com, she even lists out the calories, fat, sugar of all the recipes, some are super easy some are more complicated but everything you can imagine is there

I don't know what kind of kitchen you have however -

I make a bunch of individual size shepherds pie - cook everything and layer it into containers that can go in the freezer and oven, and wrap them up well. Just watch the water content or you end up with it being soggy once it is defrosted - I blame the potatoes.

I also love making pulled pork or chicken soup in the crock-pot. Keep out enough for a few days and freeze the rest. When the meat is on sale these can both be made fairly inexpensively.