Heat a frying pan with olive oil and fry the bacon until golden brown. Transfer the bacon to a plate and toast the bread in the remaining fat.
Place a slice of bacon, cold cuts and cucumber slices on the bread.
At the same time, boil 1 liter of water in a saucepan, salt. Gently break the egg into the boiling water and cook for 3 minutes. Remove the egg with a slotted spoon, pat dry with a paper towel and transfer to a sandwich. Repeat with the remaining servings.