Mine is from Citysuper. I have been searching for this for 1/2 yr (all supermarkets and japanese department stores) and finally found it from Citysuper. They only have limited stock at each branch, maybe you can check other branches.
My son didn' eat a lot of congee before but then I found that he is more interested if you let him involved with the food. It's VERY messy but he likes grabbing some congee and either plays with it on the table or put it in his mouth. He will eat happily from my spoon when he's occupied with the congee. If it's too messy for you, try giving him a stick of toast to eat/play with. It works for me and hope it helps u too!
I bought some organic ABC pasta in the CitySuper in TST too. Just boil it in water for few minutes like spaghetti for adult. You can serve it in chicken broth or dry with a tomato sauce, together with the minced meat and vegetable.