Whisk eggs and add black pepper and a pinch of salt.
Add some butter to a pan and scramble the eggs until set. Cover and set aside.
Rinse rocket and pat dry with a paper towel.
Fry bacon in a pan until the fat has rendered and the bacon is crispy. Set aside.
Using the bacon fat, fry the onions for about 2 minutes, and then add a splash of balsamic vinegar, salt and a bit of water. Cook over low heat until the onions are soft.
Cut bagel in half and lightly butter.
Add rocket, bacon, eggs, cheese and then onions in that order to the bottom half of the bagel.
Add top half of bagel and either cut into half or serve whole.