My mom use to make this for our family Christmas dinner. The orginal recipe said to serve this as a salad with the meal. We always served it as a dessert. I make this for covered dish dinners and once people taste it I'm asked to bring it all the time. It is light and delicious.
In a large bowl empty the boxes of Jello. Add the hot water and stir until desolved.
To that add the Strawberries, Pineapple, Bananas, and Walnuts. Mix well. Pour mixture in a large pan and place pan in the refrigerator until half way set about 1 hour. Time can be shortened if you want to put in the freezer for 1/2 hour. Don't use a glass dish if you use the freezer method. Also, keep checking on it you don't want it to freeze!
In what ever container you want to serve it in. A 5 1/2" x 11" or a 8" x 8" will work. Place 1/2 the Jello mixture. On top of that spread the sour Cream. Then top off with the rest of the Jello mixture.
Place serving container back in the refrigerator to set the rest of the way about 1 hour or over night. Then serve and enjoy.
* I double this recipe and put it in a 9" x 13" Pyrex dish and it fits real nice. It's nice to see the layers.