If adding onion I like to dice it up and put it in the microwave with the stick of butter to get a jumpstart on them cooking. If not just melt butter in microwave.

Next add both cans of corns, sour cream, eggs and salt. Mix well. Then add in butter and onions and mix well. Lastly mix in the cornbread pkg.

Pour into casserole pan and bake @ 350° for 45 to 1 hour. If you use smaller than 13X9 you will have to increase cooking time.