In a microwave safe dish combine the almond flour with the parmesan, shredded cheddar, sea salt, onion powder and baking powder. Whisk in the egg and oil until fully combined and then microwave for 90 seconds. It will have puffed up in the microwave and look like a spongy egg creation!
Heat butter in a skillet on medium high. Allow 'bread' to cool for 2 minutes, then cut in half, horizontally, to form two thiner bread slices. Fry in a skillet until the bread is nice and toasty on both sides. Cool for a couple minutes before using for burgers or sandwiches.
Don't have a microwave? Look in post above for oven instructions. :)
Whisk the mixture well enough so that the egg is fully beaten and combined well with the other ingredients.
If the egg is not fully cooked after the 90 seconds in the microwave, cook for an additional 10 seconds in the microwave.
Cool the bread just long enough to be able to work with it without getting burned - it will be very hot right from the microwave.
Be sure the skillet and butter are hot when the bread is added, this will give the bread a nice toasty colour and texture.
Nutrition facts are an estimate only! The ingredients you choose could have different nutritional values than the ingredients I have used. Deduct the fibre from the total carbs to get 1.9g net carbs for the whole bread.