Cut bagel into halves and toast them.
Heat up a nonstick skillet over medium heat. Add spinach and a splash of water. Cover with a lid and steam until wilted, about 1 minute. Season to taste with salt and pepper.
Beat eggs in a bowl with a pinch of salt
Heat up olive oil in the same skillet over medium-low heat. Add beaten eggs and scramble until desired doneness. The key to perfectly fluffy scrambled eggs without using a lot of oil is to not overcook it! As soon as the eggs start to curdle, use your spatula to gently push the cooked bits towards the center, allowing the runny egg to flow to the edge of the skillet. Continue until all the egg is almost set, then remove from heat promptly.
Assemble your sandwich: start with a bagel half, then add wilted spinach, smoked salmon, scrambled eggs, chopped chives, pepper, and finally top with the other bagel half. Slice in half for easy eating and enjoy!