I'm quite a basic cook still so some ideas to get you started sorry if they are really basic!!
Spag bol grate in a carrot and a corgette for extra veg
cottage/sheps pie add in peas, green beans, sweetcorn to meat and swede/sweet potatoe/parsnips to the mash for extr veg
chicken breasts cut a slit and add pesto, wrap with bacon or parma ham 30 mins with peas/carrots/new potatoes
chicken breast as above but cover in either cherry tomatoes (really squash them in!!) or slices of tomatoes good slug of olive oil and add chopped peppers with veg.
par boil broccolli and cauli for 5 mins drain into dish cover with cheese sauce, breadcrumbs and grated cheese bake for 30 mins at 220 with roast or boiled pots and carrots. Souns nothing but it is SCRUMMY!!!!
fry leeks, bacon bits and chicken strips in butter for 5 mins, into dish cover with cheese sauce as above but cook at 200. Also nice topped with sweet potatoe mash.
sweet potatoe, corgette, aubergine, onion and pepper chopped, drizzle in olive oil roast for 20 mins at 220 then add pasta small like macaroni works well) pasta sauce and half pint boling water, cover in foil and cook at 200 for antother25 mins.
nice sausages with suede and sweet potato mash and peas/carrots/sweetcorn/green bean/cauli etc
fry bacon bits and olives add to cooked pasta and stir in for 5 mins pesto
fry bacon bits and leeks in butter for 5 mins add to pasta and a cheese sauce - change to whatever other veg you like for quick dinners