The simpler a recipe is the more crucial it is to use great ingredients. You can't cover up inferior ingredients through the cooking process.
For a breakfast sandwich the key components are always your bun and whatever is the main filler in the sandwich. A breakfast sandwich is most often filled with soft ingredients so having a hard bun will likely end with the ingredients being pushed out the other side of the bun as you eat it. Finding a good brioche bun for this recipe is well worth it.
Makes 4 sandwiches