(soy beans)Edemame(frozen and shelled) are a great choice. It's yummy and nutritious and kids usually like picking it up with there fingers.
Also cut up sweet potatos like french fries and bake them with some olive oil in either an oven or toaster oven. Pureed soups are a yummy way to get the veggies in. (butternut squash-tomato-split pea-carrot etc.)
flax oil is the best-you can put it in anything and they don't know it's there. It's extremely nutritious and is good for BM's. Never cook with it and always refridgerate. You can also do plain potatos in the oven as french fries.
Avacados are good in yogurt or mashed or in chunks. Raw almond butter(trader joe's has it for $5 a jar). Soy milk instead of milk...earth balance(butter) or soy garden instead of butter-it's very good. Food for Life(Ezekiel 4:9) makes great breads and tortilla wraps that are made with sprouted grain flour. There's 16 grams of protien in them. They're easy to warm up and make a dairy free pizza with. Also good with raw almond butter spread on top. I usually warm them in toaster oven-short time for soft and a little longer for crispy. Anyway I know this was long but I hope it's helpful.