Ester,
what kind of congee you gave to your baby? As the cereal is sweety, baby may not like the taste of congee. You can put 'mug joe' (1/2 pcs in the beginning then reduce the portion to 1/4...etc) and they will eat it. You can also put sweet potato or pumpkin.
I put 4 spoons of cereal mixed with 2 oz of milk, he liked it at first, but now after tasting the banana thing, he refused to take cereal anymore..
Btw, is the banana thing consider a main meal or desert?