I'm also a student in my 3rd year so feel your pain. Buy yourself a garlic crushed for a couple of quid - it will save you hours over the term time. I've never really learnt to cook, just been experimented.
Breakfast is porridge or cereal if I have it - some days after a few hours sleep I just cannot stomach porridge as it takes so long to digest.
Spag Bol:
red onions in, chopped peppers (or any veg), mince and garlic - fry that, and once cooked add half a can or so of chopped tomatoes. Keep your chinese takeaway cartons and fill these up and you have a few meals there. Personally I cook the spaghetti each time rather than reheating. Super cheap but not that much veg, does the job though!
Lemon chicken - best done with a friend to keep costs low:
Fill your deep sided oven tray with chicken - wings work the best, thighs seem to take the longest to cook. crush two cloves of garlic and rub into the chicken (spike the chicken with a fork first so you can rub the garlic in more). Splash cooking oil or olive oil over the chicken, and then squeeze between two and four lemons all over the chicken - you can even place chopped lemon slices over the chicken. Get a couple of red onions, chop into fair chunks and throw these on and around the chicken, just cover it all in a big onion mess. Grab a few peppers, chop them into long slices and put these between the gaps of the chicken. Now your potatoes, cut into thing slices and put them where ever there is room. Boom, all your meal in one tray, and if done right tastes amazing!
Stir fry - I lived off these first year:
noodles on the boil, chicken or beef chunks in the frying pan, throw in whatever veg you have - runner beans, mange tout, broccoli, peppers, onions or best of all bean shoots- add sauce when the meat is cooked (soy sauce or whatever stir fry sauce you have)
Pasta bake is another good one, can be saved in the fridge easily.
Jacket potato! eat the skin.
feeling veggie? Thinly chopped potato slices, whatever veg you have, onions, throw into the frying pan. When the potato is nearly cooked add a can of chopped tomatoes and there is your veggie meal. Pretty healthy.
Reduced salmon available? excellent... pepper the salmon and then throw the salmon with the skin on into the frying pan, about mid heat. Skin side down let it cook for a few minutes. The skin will go crispy but the salmon should be fairly cooked. Then do a minute or so on the top, so skin side facing upwards. Fingers crossed it is rare in the middle and ready to go.
Rushed for time at lunch? Ham, bread, butter, beetroot. Ham and beetroot sandwiches are amazingly healthy.
Egg friend rice: cook your rice, then into a frying pan, add frozen peas and an egg - fry.
In general, keep stocked up on chopped tomatoes, onions, garlic and potatoes - if you can afford it, peppers, you can do a lot with these.
When you cook pasta/spaghetti, a drop of oil and a pinch of salt doesn't go amiss.