Mix together cream cheese and green onions together in a small bowl.
Divide and spread cream cheese mixture on 2 slices of the bread. Sprinkle everything bagel seasoning over the cream cheese. Add mozzarella over the everything bagel seasoning.
In a large nonstick skillet, melt half of the butter over medium-low heat. Add in pieces of bread with cream cheese mixture. Top with remaining pieces of bread. Cook until lightly golden, about 4 to 6 minutes.
Flip. Add remaining butter. Cook until lightly golden, about 4 to 6 minutes. Remove sandwiches and plate on 2 plates.
To top:
On top of the sandwiches, stack tomato, then onion, then cucumber. Top vegetables with salmon. Garnish with chives. Serve immediately.