To start - I eat a lot of veg so some of these ideas might not be where your tastebuds are at, but here's some random ideas:

• Grated carrot, grated zucchini, any grated squash and spinach (buy baby spinach or those little frozen spinach cubes), frozen peas aren't overpowering and can be cooked into anything that's vaguely stew-y. Hide a fistful in bolognese, quiches, pies and sausage rolls (carrot only - the others are too wet), even risotto etc. just cook them in.
• The white and brown button mushrooms that are most common aren't too strong and are still good for you. If you are making gravy, chuck in some onion and a couple of mushrooms (fry them up) or add to any of things in the last dot point.
  • Take advantage of the gravy to add one more veg to your plate. Peas, carrot etc. Just a spoonful of something that's a different colour
• You can make a simple potato bake by layering thinly sliced potatoes, onion and grated cheese in a small baking dish and cook until soft and cheesy (you can pre-microwave it for a few mins). You can add in a layer or two of sweet potato, cauliflower sliced flat. You can also add some fresh chives and parsley or thyme for a little extra green.
• Scrambled eggs? Add little bit of baby spinach (cut it even finer) or one mushroom (fried first). And chives or sage.
• making a satay? add a red capsicum chopped into little strips or cubes
• stir frying some other meat - broccolli (but only if you have a yummy stirfry sauce. Broccolli is amazing for fibre but it can taste ick if you aren't already a fan. If not, add some carrot sticks.
• Onion + tomato gravy: fry an onion and add a couple of tomatoes (chopped) and some mustard and salt-pepper. Cook it down until it gravy-fies. you may need to add a smidge of water. This is excellent on sausages.
• If pumpkin is not too strong, roast some pumpkin and add to a risotto (roasting it first with salt/pepper/oliveoil makes it more roasty and less vege tasting if that makes sense).

Advanced level/final boss:

• If you like tomato/onion/garlic type flavour - one of my favourite winter things is a big tray of roast veg. Sweet potato, beetroot, caulliflower, couple of mushrooms, carrot, anything that's not going to fall apart. Get a tray that's a smidge small (so its sort of piled in) and add your vege + onion (in wedges) + tomatos (wedges) and some garlic (peeled). Plus cubes of halloumi cheese. Salt+pepper+olive oil+ balsamic vinegar. In 30 mins you have yourself a vege/tomatoey/salty pile that you can serve with pasta, chicken etc.

Anyway - just a braindump. I can look up some actual recipes if that helps too.

I have a vegie fussy child. I will grate cauliflower, broccoli, zucchini, carrot etc extra fine and freeze it in snaplock snack bags. I hide a bag in anything I can, like home made burgers and even home made nuggets with cauliflower hidden in them. Spaghetti bol gets 2 bags. A white pasta sauce will get the pale vegies hidden with lots of herbs to hide them. Zuchini slice becomes egg and bacon slice and the green bits I say are herbs. Blended soups work, as does putting some cheese sauce on top of some steamed veg. Alternative textures and shapes, spiralised carrot and zucchini noodles, However it gets in!