Toast the bagel

• Slice the bagel in half and spread butter on the cut sides.
• Toast the halves in a pan until golden and crisp.

Cook the egg

• Fry the egg in the same pan to your liking.
• Season with salt and pepper.

Mash the avocado

• Mash the avocado in a bowl and season with salt and pepper.

Assemble the sandwich

• Spread the mashed avocado on the bagel halves.
• Top with the cheese slice and the cooked egg.
• Close the sandwich and serve warm.