Preheat the oven to 200°C.
Wash and dry the 500g new potatoes. Place them in a roasting tin, drizzle with 1 tablespoon olive oil, toss to coat, and sprinkle a generous pinch of salt over them. Arrange the potatoes in a single layer.
Roast the potatoes in the preheated oven for 20–30 minutes, turning once halfway through, until they are tender when pierced with a knife and crispy on the outside.
While the potatoes are roasting, stir together 100 ml sour cream and 1 tablespoon chopped fresh chives in a small bowl. Set this mixture aside and reserve a little of the chopped chives for garnish.
Cut the 100 g smoked salmon into small strips.
When the potatoes are done, remove them from the oven and let them cool just until they can be handled (about 5 minutes). If you prefer to serve them cool, allow them to cool completely before proceeding.
Once cool enough to handle, use your fingers to gently pinch each potato near the top and squeeze to open it into the classic baked-potato shape.
Spoon a portion of the sour cream-and-chives mixture onto each opened potato, then top with one or two strips of smoked salmon.
Garnish each potato with the reserved chopped chives and serve warm or cool, as desired.