Preheat your oven to 350°F and lightly grease a large oven-safe ramekin or a muffin top pan with a drop of avocado oil.
In a small bowl, whisk together the large egg and the egg whites until well combined, then pour the mixture into the prepared ramekin.
Bake the egg for 12-15 minutes or until the center is firm and set.
While the egg bakes, combine the ground turkey, garlic powder, onion powder, sage, sea salt, and black pepper in a bowl, mixing by hand to incorporate the spices.
Form the turkey mixture into a wide, flat patty that is slightly larger than the English muffin.
Heat the avocado oil in a skillet over medium heat and cook the turkey patty for 4-5 minutes per side until browned and cooked through.
Split the English muffin and toast it until the edges are golden and crisp.
Assemble the sandwich by placing the turkey patty on the bottom muffin half, followed by the baked egg disk and the slice of cheddar cheese.
Place the top half of the muffin on the cheese and let it sit for 30 seconds to allow the cheese to melt slightly.
For meal prep, allow the muffins to cool completely before wrapping them tightly in parchment paper or foil and storing them in the refrigerator.