If you have a smoker or a smoker box for your grill, smoke salmon for 15 minutes. Otherwise, pan-fry it skin side first to your liking (I like the skin crispy, the other sides seared and the centre rare).
Slice the radishes and cucumber. Mix with the lentils and salad leaves and season with lemon zest and juice, extra virgin olive oil, salt, pepper and sumac.
Whisk the dressing ingredients in a small bowl. Depending on the tahini, you might need to add more water to make the dressing loose enough to drizzle.
Serve salad topped with salmon and drizzle dressing on top.