This went down so well with 2 very little Gdcs the other day - 10 months and nearly 2 - so I thought I'd post here in case anyone else was interested.
I fried a little finely chopped onion very gently, then added some short grain (ordinary pudding) rice and fried that v gently. Then added water, with salt free baby veg stock from Boots, and a lot of finely chopped veg - carrots, mushrooms, peppers and celery, plus some tomato purée, and simmered till rice was soft and virtually all the water was absorbed.
Served with grated cheese stirred in. They ate loads!
Will definitely make again.
Terrible relationship with DIL - am I the problem?

