French Onion Casserole

First make the bread. Preheat the oven to 350 degrees F
In a medium-sized bowl, combine the flour, psyllium powder (no substitutes: flaxseed meal won't work), baking powder and salt. Mix until dry ingredients are well combined.
Add in the eggs and vinegar and mix until a thick dough.
Add boiling water to the bowl. Mix until well combined and dough firms up.
Form into a large sub/loaf and place onto a greased baking sheet. Bake for 65 minutes.
Remove from the oven and allow the bread to cool completely. Slice the bread into 1 inch thick slices (spread butter on each slice if desired). Toast in the oven on a cookie sheet at 375 degrees F for 8-12 minutes or until golden brown. (THIS recipe will make extra bread slices, only use 8 thin slices or 1/3 of the loaf)
Next, make the casserole. Slice the onions very thin. Place the onions, butter, beef broth, thyme, and salt into a 4-quart crockpot. Cover and cook on high for 4 hours or until the onions are brown and caramelized.
Once the onions are brown, uncover the crockpot and top the onions with 1 cup shredded cheese. Top with toasted bread slices. Push the bread slices under the sauce and top with the remaining cheese. Keep the crockpot on high and cook until cheese is melted about 20 minutes.