Finely chop the onion. Place in a pan with 2 tbsp butter, the broccoli florets, and cubed chicken breast. Sauté until soft.
Preheat oven to 325F.
In a mixing bowl, combine the almond flour with the remainder of the butter (you can soften it beforehand) to make a crust. Press 75% of the mixture onto the bottom of a 9” pie tin. Place in the oven for 5 minutes.
Mix 6 eggs and 1 3/4 cups heavy cream together in another mixing bowl. Add in nutmeg and cayenne.
Pour onion/broccoli/chicken mix evenly on top of almond flour crust in the pie tin. Sprinkle a layer of cheese over top.
Pour egg mixture into the pie tin.
Sprinkle the top with the remainder of cheese and almond flour mixture for a crumble top.