Preheat the oven to 425˚F and place a baking sheet in the oven to get hot while it is preheating.
Cover potatoes with 2 inches of cold water and bring to a boil and add 1 teaspoon of kosher salt. Parboilthe potatoes for 5 minutes then drain in a colander.
Pull the preheated sheet pan out and drizzle the olive oil all over the pan. Add the parboiled potatoes and shake the pan gently to coat the potatoes in oil. Sprinkle potatoes with salt and pepper.
Bake for 10 minutes then take the pan back out of the oven. Use a potato masher to gently smash thepotatoes to about half of their height and so they spread out a little to increase their surface area.
Return the pan to the oven and bake for another 5-10 minutes until the potatoes are nicely browned andcrispy.
Transfer the smashed potatoes to a platter and spoon a small dollop of greek yogurt onto each. Thenplace a bite sized piece of smoked salmon on top of the greek yogurt. Sprinkle the tops with choppedchives or dill and fresh lemon zest.