Thaw salmon days in advance in the fridge, I used frozen salmon. Peel and chop potatoes (I did this like mad since I had no time) Can leave peels if they're good. Drizzle oil, season with salt and black pepper, mix potatoes in pan and layer it flat and chop lemon slices, put one under and on top of each salmon, throw whatever is left on top of the salmon (also seasoned with a bit of oil, salt and black pepper. )
Last minute while oven heating up I sprinkled some lemon pepper and hungarian sweet paprika on top too.
Bake at 400 until potatoes are tender and edges are crisp, by that time salmon should be good too. I took it out first time I checked as I like the salmon tender and not dry.