Boil the potatoes. Place the potatoes in a pot and fill it with enough water to cover the potatoes by an inch. Salt the water (I use about a tablespoon of kosher salt). Bring the pot to a boil over medium-high heat, then cook the potatoes until fork-tender, about 22 to 25 minutes.
Drain and cool. Drain the potatoes in a colander and let them cool to the touch, about 10 minutes.
Season and flavor. Preheat the oven to 450°F (230°C). Transfer the potatoes to a mixing bowl, then add the oil, and everything bagel seasoning. Stir to fully coat the potatoes in the seasoning.
Smash the potatoes. Place the potatoes on a small baking sheet and use the bottom of a wide-bottomed glass to smash them down. Aim for a height of about ¾-inch. Bake until the potatoes are lightly golden on the top, about 25 minutes.
Top the potatoes as bagels. Once the potatoes have cooled a bit, spread some cream cheese on top, top with smoked salmon, a few thin slices of red onion, some capers, and a few small sprigs of fresh dill.
