In a frying pan over medium heat, add chopped bacon in. Once the bacon fat starts to melt, add onion and ground beef. Season with salt and pepper and cook until the beef is brown.
Transfer the mixture into the bottom of an 8-inch pan then top with shredded Gouda cheese and then place cheddar cheese slices on top to cover it.
In a medium-size mixing bowl, combine egg, almond flour, heavy cream and a little bit of salt and pepper. Stir until creamy then pour the batter in the prepared baking dish on top of the cheese slices.
Bake in the oven for 25 minutes. Let the pie cool for a while before cutting. Serve warm and enjoy with some salad and leafy greens.