Place bagel halves cut-side up in toaster or under broiler. Toast 3–4 minutes at medium heat until edges are golden brown and surface feels crisp. Remove and let cool 1 minute to prevent cream cheese from melting.
1 whole bagel
Spread 1 to 1.5 tablespoons softened cream cheese evenly on each bagel half using a thin ⅛-inch layer. Add lemon zest or black pepper on top of cream cheese if desired.
3 tablespoons cream cheese, 1 wedge lemon
Drape 1 to 1.5 ounces smoked salmon over cream cheese on each half, folding to cover evenly without gaps. Press gently to help salmon adhere.
3 ounces smoked salmon
Arrange 1 to 2 thin red onion slices over salmon, then scatter capers evenly. Add fresh dill and optional cucumber slices if using.
2 slices red onion, 1 teaspoon capers, 1 tablespoon fresh dill
Squeeze lemon wedge over assembled bagel halves and add black pepper to taste. Slice in half with a sharp serrated knife to avoid squashing. Serve immediately while bagel is still crisp.
1 wedge lemon
