Simple, quick and tasty - with an authentic Teriyaki marinade made from only three ingredients
There's really very little to this - the beauty of it lies in the simplicity of the ingredients. Salmon goes so well with soy and sweet flavours and takes minutes to cook.
This is delicious served with my sesame-miso asparagus (59 calories per serving) and cucumber-radish pickles (14 calories per serving) accompanied by some rice (or cauliflower rice if you're avoiding carbs) and you can knock all of these dishes up in under half an hour if you're canny about it (I'll post a method for cooking the whole meal separately).
This serves two people, at 336 calories per person.
I prefer to use skinless salmon fillets (if yours have skin on, don't worry they're easy to skin - just put them skin side down, make a cut just above the skin, and hold onto the skin - use kitchen towel or a tea towel if you find it difficult to grip, or slip your knife through the skin to make a hole to hook your finger through - and use a gentle sawing motion cutting away from you whilst pulling the skin towards you and keeping the knife close to the board until you reach the end of the salmon), as unless you descale the salmon, there's a risk of scales ending up in your sauce, and the skin isn't going to crisp up too well without the risk of burning due to the sugars in the marinade.
[Calories in square brackets, if you're counting]
2 boneless, skinless salmon fillets, around 120g each 
2 tbsp mirin (check ingredients for gluten free brands vary) 
2 tbsp soy sauce (preferably Japanese, e.g. Kikkoman - use tamari for gluten free) 
2 tsp sugar (golden caster - or you could substitute honey ) 
1 tsp neutral flavour oil, or a dozen sprays of pure oil from a pump spray (e.g. sunflower, or to suit your diet) 
1 tsp sesame seeds 
(If you want to mix it up a bit, you could also add grated ginger, garlic and chilli to the marinade and include sliced spring onions as an aditional garnish - see notes below)
Put mirin, soy and sugar (or honey) in a non-metallic dish which will snugly contain the salmon fillets (or you could use a sandwich bag), stir to dissolve sugar and put the salmon fillets into marinade, ensuring evenly covered.
Set aside while you prepare any other side dishes you're going to have with it, 20 to 30 minutes is great if you can - if it marinades a little longer, then even better.
Toast the sesame seeds in a good, non-stick dry pan (that you can later use for cooking the salmon) until starting to turn golden brown, and remove immediately and set aside.
Remove the salmon from the marinade, shaking off any excess and patting dry. Add 2 tbsp water to the marinade and set aside.
Add the oil to the pan, and put over a medium heat. Swirl the oil around until the pan is hot and evenly coated, then add the salmon steaks top/best side down. Cook until you can see that they are cooked about 1/3 of the way through (where the flesh becomes opaque/light pink - should only take a couple of minutes, but will depend on whether your fillets are thin and tall, or wide and flat) and then turn them over, gently.
Add the reserved marinade to the pan, and continue cooking until the other side is cooked about 1/3 of the way up on the thickest part (the salmon will continue to cook from the residual heat after you've removed it from the pan, and this will give you juicy and moist salmon - but if you're not comfortable with this, or slightly 'pink' salmon, then cook a little longer) then remove the salmon (leaving the marinade in the pan) and put on your serving dishes.
Turn the heat up to high, until your marinade is bubbling, and reduce until thickened somewhat, swirling in the pan (this won't take long, but be careful it doesn't burn around the edges of your pan, or it will taste bitter) then pour over your salmon steaks, and top with a sprinkling of the toasted sesame seeds, and enjoy!
If you want to change the flavour profile a little, and stray from tradition, you could add some grated ginger (an inch or so) and a clove of crushed garlic to the marinade, maybe even some sliced red chillies, and top with some finely sliced spring onions (scallions) when serving.