If the huge supermarket is a Sainsburys, get the magazine for this month. Loads of healthy recipes in it this month.
Jamie's 30 minute meals is also a brilliant book.
Healthy dinners:
Pork chops with some spices rubbed on, grilled, with some roasted veg done in oven with some olive oil and seasoning on - we like to do butternut squash/sweet potato, cherry tomatoes, red onions, peppers, mushrooms, courgette and sometimes asparagus.
Make yourself a burger using lean steak mince, serve it in a brown roll, or by itself, with salad
Vegetable frittata - can throw what you like in. I like to do courgette and peppers mixed with egg and a thinly sliced potato.
Teriyaki tuna steak, done with some brown rice and oriental veg - I do spring onion, broccoli, pak choi, asparagus, in a wok with some red chilli and soy sauce.
Salmon tray bake from Jamie's 30 minute meals - salmon, prawns, cherry tomatoes, asparagus, lemon, coriander, bit of pancetta to add a little saltiness and some anchovy. All done in a roasting tin under the grill. Brilliant.
Chicken salad - get yourself some interesting things such as olives, artichoke, roasted peppers to throw in. Coat your chicken in some interesting herbs/spices before you cook it. I sometimes use a fajita mix on the chicken.
Simple mediterranean fish stew - some white fish such as haddock, cod or river cobbler is fine, done with some shallots, peppers, 2 x tins of tomatoes, some frozen mixed seafood (prawns, mussels, calamari) thyme, parsley, capers, white wine (optional) bay leaves, s+p. Simple but awesome.
Chicken cacciatore - tin of tomatoes, skinless chicken breasts, olives, capers, onion, can't remember what else, sure you could find a recipe - serve with brown rice or pasta if you like.
Lunch-wise, how about things such as wholemeal pittas with chicken and salad, bit of sweet chilli sauce or low-fat caesar dressing to pep it up a bit?
Soup? Covent Garden soups are good, and filling.
Baked potatoes are always good. I don't like them straight from microwave so I'd be tempted to cook it in the oven at home then reheat in microwave at work.
All I can think of right now!