Root veggies make a great addition to mashed potatoes. The first time we did it was with carrots, which were awesome, but the best is caramelizing some parsnips and mashing them in. Tasty, tasty.
Another way to get a picky non-vegetable inclined person to eat veggies (though it doesn’t hide them in the least) is kale chips. I love kale chips. You take kale, rub it with olive oil, sprinkle salt and pepper, then put it in the oven at a very low temperature. It’s like healthy potato chips. They don’t taste strong at all—mostly just crunchy and salty.
There is an old saying, “everything is tastier with bacon”. I use bacon to flavor a lot of veggies—particularly Brussels sprouts.
Zucchini bread is absolutely delightful.
If the kids like pasta, I always think that spaghetti squash is really fun. I fix it just like pasta—sauce, cheese, etc. It doesn’t really taste the same, but it’s super fun.
Meatloaf. You can put a metric ton of carrots and onions into meatloaf.
One of my friends has a recipe for roasting cauliflower and chick peas where the spice mix ends up making it taste a lot like Doritos. I will try to find it.