Creamy Beef & Green Bean Casserole

It's so exciting to find a paleo casserole recipe!  One dish meals are so appealing when we have places to go in the evening.  I did my own version of this casserole recipe.  I have loads of onions in my garden right now, so I am not inclined to purchase pearl onions or shallots.  Also, I had baby portibello mushrooms I was needing to use, so I used those. I also have fresh green beans, so I used those.  All these adjustments could have made a difference, but we loved this!  It was a little liquidy, so I may increase the arrowroot next time.  We definitely will be making this again, so I will try to update if that makes a difference.