Preheat oven to 350 degrees. In medium size casserole dish add: corn, green beans, onion, cheese, cream of celery, and sour cream. Mix it all together until it is well incorperated. ***(Do drain the corn and green beans!)***
Take one, unopened pack of ritz crackers and crumble it (while in pack). TIP: I drape a kitchen towel over it had pound it softly with my palm.
Melt the stick of butter in a small sauce pan on the stove, OR melt butter in a microwave safe bowl in microwave. Once its melted completely, add the ritz cracker crumbles and stir until butter coats the crumbs.
Pour the ritz cracker crumbs on top of the casserole until it is completely covered. Depending on the size of casserole dish, you may need to repeat step 2 and 3 to cover casserole completely.
Place casserole in the oven and bake for 45 - 50 minutes. Once it is finished baking, allow it to rest about 15 minutes before serving. SCRUMPTIOUS aint the word!!! :)