Preheat your oven to 375F (190C).
Wash your new/baby potatoes well before adding to large pot with cold/room temp water. You can cut some in half or quarters to keep them relatively the same size if needed!
Add salt to the water.
Place on the stove and turn the stove on high heat; cover until the potatoes come to a boil (keep an eye on it closely, you don't want it to boil over!)
Uncover the pot and boil for approximately 15 minutes or until tender. Adjust your stove if necessary to keep them boiling.
If you prefer, you can roast potatoes by placing them on a lined baking sheet with olive oil, salt, pepper, and garlic powder - coat the potatoes well, then place in the oven and roast for at least 30 minutes or until tender.
While the potatoes are boiling, prep your salmon fillets (you can buy precut, or slice a larger side of salmon at home!) by seasoning with salt and pepper, and optionally garlic powder.
Heat an oven safe pan over medium to high heat; once hot, add a few tablespoons of olive oil or neutral oil, and place your salmon fillets skin side down in the pan.
Cook for about 5 minutes without moving the fillets around.
After 5 minutes, flip the salmon, then transfer the pan to an oven to cook for 10-15 minutes, or until the salmon registers an internal temperature of 145F (62C).
After you transfer the salmon to the oven, make sure to check on your potatoes - if they're done, drain them and leave them in the pot! If they still need a few more minutes, make sure to keep an eye on them while you're working on the dill sauce.
While the salmon is in the oven, it's time to make the dill sauce.
Place a small pot on the stove over medium heat and melt 2 tbsp of butter.
Whisk in flour and cook for about a minute with the butter. It won't get too thick, but make sure you keep whisking to prevent it from burning.
In a measuring cup, add your milk and cream together.
Pour milk and cream slowly into the pot with the roux (butter and flour), whisking constantly to prevent lumps.
Once you've added all the milk and cream, whisk and make sure the mixture is bubbling at the edges.
If the sauce is too thick, add a little bit more milk.
Add in chopped dill, salt and pepper, and whisk well. Cook for just another minute, whisking constantly.
Add 1 tbsp of butter at the end and turn off the heat, whisking until the butter is incorporated.
Taste for seasoning and adjust salt levels if needed.
The salmon should be done at this point - remove from the oven and let rest for 5 minutes. If your potatoes were not done previously, make sure to check them and drain the water, or if they are roasting in the oven, check for tenderness. Remove from heat/remove from the oven.
Keep the dill sauce warm and whisk before serving. If it does thicken up, add a tiny bit more milk.
Serve the salmon and potatoes all together on a plate for a family style/dinner party meal, or make individual plates. Cover with sauce and garnish with chopped chives or additional dill sprigs! Enjoy!