In a large bowl combine all the ingredients except the cream corn and kernel corn. Whisk until well combined. Make sure there are no lumps from the cornstarch.
Add in the cream corn and kernel corn. Mix well.
Grease a 9x7in casserole dish with butter.
Pour in the mixture.
Bake at 375 degrees for 30-35 minutes or until the top is golden brown.
Allow to cool for at least 10 minutes before serving. This dish can be served warm, at room temperature, or cold.