Season the ground beef with all of the condiments. Crack the egg into the beef and add in the almond flour as well. Knead until well combined. Mold into 4 meatballs.
Create the hollow shape of the meatballs with a soda can. Using your hands, shape the beef to form a cup before removing the can.
Fill the molded beef with a mushroom. Wrap a slice of bacon around the sides of the cup.
Lay a slice of cheese on the surface of the hamburger to cover the mushroom. Cook in the 300°F oven for 10 minutes. Remove once the meat is cooked.
Lay another slice of cheese on top and rebake for an additional 5 minutes, enough to melt the cheese.