We ourselves are eating some things we didn't eat before PKU, because it has helped familiarize Jeffrey with the core fruits and vegetables of the diet. One night when we had guests over, we baked onions in foil on the grill with a pat of margarine and salt. Jeffrey saw everyone else eating their onions and ended up eating a lot of baked onions. A similar thing happened when we cooked fresh pumpkins with the grandparents and all began eating it. You'll be surprised what your young child will eat.
Conditioning definitely affects food choices.
Another trick is to offer just a little at a time. A half cup of cranberry sauce can look pretty overwhelming to a 1 year old. Let them sample it and often they will eat or ask for more. With each new food, you are breaking new ground and your child is learning. Involve your young child in food choices by talking to them.