Set your oven to 430⁰F/220⁰C, combination steam setting. If your oven has variable steam, use 50% (if not, don't worry! Just set to combi steam at the correct temperature and the oven will work out the steam level for you).
Put the potatoes and olive oil into a stainless steel pan and season well with salt and pepper. Toss to coat the potatoes and cook until the potatoes are golden and tender, about 25 minutes. Remove from oven and increase the heat to 450⁰F/230⁰C.
Use a spatula to loosen the potatoes from the bottom of the tray and push them all over to one side, so you’ve got half the tray sitting empty.
Place the salmon on the empty side of the tray and dot the butter all over it. Arrange a few lemon slices on each fillet and season with a little salt and a liberal amount of pepper. Spread the asparagus over the top of the cooked potatoes in a (roughly) single layer (no need to worry if a few of the spears overlap).
Return the tray to the oven for 4-5 minutes, until the salmon is cooked to your liking. 5 minutes gives me ‘medium’ cooked salmon – not raw but slightly blushing in the middle, so you can adjust either way to get less or more cooking.
Serve immediately with extra lemon for squeezing over the vegetables if you like.
Method 2 – Steam Only:
Set your oven to 212⁰F/100⁰C, steam setting (100% steam).
Put the potatoes into a solid stainless steel tray and season well with salt and pepper. Cook for 25 minutes, by which time the potatoes should be tender.
Push the potatoes over to one side, so you’ve got half the tray sitting empty. Place the salmon on the empty side of the tray and dot the butter over it.
Arrange a few lemon slices on each fillet and season with a little salt and a liberal amount of pepper. Spread the asparagus over the top of the cooked potatoes in a (roughly) single layer (no need to worry if a few of the spears overlap).
Return the tray to the oven for 5-8 minutes, until the salmon is cooked to your liking. 7 minutes gives me ‘medium’ cooked salmon – not raw but slightly blushing in the middle, so you can adjust either way to get less or more cooking.
Serve immediately with extra lemon for squeezing over the vegetables if you like.
Notes
Note there are two different cooking methods here! Follow method 1 if you have a combi or convection steam oven, or method 2 if you have a steam-only oven. I generally use skin-on salmon fillets but skinless is completely fine. I cook my fish skin-side down and the skin holds it together well for serving – we just flake the fish off the skin as we eat it.