1. Peel the potatoes and place them in a large pot of salted water, making sure they're covered. Bring the water to a boil at 212°F (100°C), then reduce the heat to a gentle simmer at 180°F (82°C) until the potatoes are tender.

2. Once the potatoes are done, drain them and cut them in half lengthwise. Wrap them in a towel to keep warm.

3. In a medium saucepan, whisk together 2 tablespoons (30g) of all-purpose flour and 1 cup (250ml) of milk. Place the saucepan over medium heat and bring the mixture to a boil, whisking constantly.

4. Reduce the heat to a simmer at 160°F (71°C) and let cook for 3-5 minutes, or until the sauce thickens. If the sauce becomes too thick, add a little more milk as needed.

5. Season the sauce with salt, pepper, and a pinch of lemon zest. Stir in 2 tablespoons (6g) of chopped fresh dill.

6. Add the warm potatoes to the sauce and stir until they're well coated.

7. Serve the dish with 4 slices (120g) of smoked salmon, lemon wedges on the side, and a fresh green salad.